UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

FORM N-CSR

CERTIFIED SHAREHOLDER REPORT OF REGISTERED MANAGEMENT INVESTMENT
COMPANIES

Investment Company Act file number 811-21597

PRIMECAP ODYSSEY FUNDS
(Exact name of registrant as specified in charter)

225 SOUTH LAKE AVENUE, SUITE 400
PASADENA, CA 91101
(Address of principal executive offices) (Zip code)

MICHAEL J. RICKS
225 SOUTH LAKE AVENUE, SUITE 400
PASADENA, CA 91101
(Name and address of agent for service)

(626) 304-9222
Registrant's telephone number, including area code

Date of fiscal year end: OCTOBER 31

Date of reporting period: APRIL 30, 2011

ITEM 1. REPORTS TO STOCKHOLDERS.

SEMIANNUAL REPORT

For the Six Months Ended April 30, 2011

LOGO PRIMECAP(R)
------------ ODYSSEY FUNDS

PRIMECAP ODYSSEY STOCK (POSKX)

PRIMECAP ODYSSEY GROWTH (POGRX)

PRIMECAP ODYSSEY AGGRESSIVE GROWTH (POAGX)

TABLE OF CONTENTS
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------

Letter to Shareholders ................................... 2

Performance Graphs

PRIMECAP Odyssey Stock Fund ....................... 9

PRIMECAP Odyssey Growth Fund ...................... 10

PRIMECAP Odyssey Aggressive Growth Fund 11

Expense Example .......................................... 12

Sector Breakdown ......................................... 14

Schedule of Investments

PRIMECAP Odyssey Stock Fund ....................... 16

PRIMECAP Odyssey Growth Fund ...................... 20

PRIMECAP Odyssey Aggressive Growth Fund ........... 25

Statements of Assets and Liabilities ..................... 29

Statements of Operations ................................. 30

Statement of Changes in Net Assets

PRIMECAP Odyssey Stock Fund ....................... 31

PRIMECAP Odyssey Growth Fund ...................... 32

PRIMECAP Odyssey Aggressive Growth Fund ........... 33

Financial Highlights

PRIMECAP Odyssey Stock Fund ....................... 34

PRIMECAP Odyssey Growth Fund ...................... 35

PRIMECAP Odyssey Aggressive Growth Fund ........... 36

Notes to Financial Statements ............................ 37

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------

DEAR FELLOW SHAREHOLDERS,

For the six months ending April 30, 2011, the PRIMECAP Odyssey Stock Fund,
PRIMECAP Odyssey Growth Fund, and PRIMECAP Odyssey Aggressive Growth Fund
produced total returns of +15.72%, +17.39%, and +20.00%, respectively. By
comparison, the unmanaged S&P 500 Index (S&P 500) produced a total return of
+16.36% for the period.

The U.S. stock market provided strong returns during the six months ending April
30, 2011, extending the rally that began last summer as the economy continued
its recovery from the recession. Gross domestic product (GDP) has increased for
the past seven quarters. Both consumer spending and industrial production have
increased as consumer confidence has improved and companies have rebuilt
inventories and returned to growth mode.

However, there are reasons for caution regarding the sustainability of this
recovery. Unemployment remains stubbornly high, housing markets show minimal
improvement, the U.S. dollar has weakened relative to other major currencies,
and balancing budgets at the federal, state, and local government levels poses
daunting challenges. More recently, unrest in the Middle East and North Africa
has added risk to an already elevated oil price, and the tragic earthquakes in
Japan have disrupted the supply chains of many companies.

As always, the PRIMECAP Odyssey Funds remain focused on investing in companies
that, in our judgment, offer better growth prospects than are currently
anticipated by the market. We continue to be overweight in the health care and
information technology sectors and underweight in the energy sector in each of
the three PRIMECAP Odyssey Funds.

This sector allocation generally hurt the funds' results during the first six
months of the fiscal year, as returns in both the health care and information
technology sectors trailed the overall S&P 500 while the energy sector, fueled
by rising commodity prices, enjoyed the highest returns of any sector. However,
positive stock selection more than offset an overweight position in the
information technology sector in each of the PRIMECAP Odyssey Funds. Each fund
also benefited from underweight positions in the consumer staples, financials,
and utilities sectors. Favorable stock selection in the health care sector also
helped results in the PRIMECAP Odyssey Growth and PRIMECAP Odyssey Aggressive
Growth Funds.

A more detailed discussion of the results of each PRIMECAP Odyssey Fund follows.

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY STOCK FUND
--------------------------------------------------------------------------------

From November 1, 2010 to April 30, 2011, the Stock Fund's total return of
+15.72% trailed the S&P 500's total return of +16.36%. On a relative basis, poor
stock selection in the energy and materials sectors, along with an underweight
position in the energy sector, detracted from the fund's returns. The fund's
results were also hurt by its sizeable cash position during the period. This was
partially offset by positive stock selection in the information technology
sector.

L.M. Ericsson, Altera Corp., and Biogen Idec Inc. were among the top
contributors to the fund's relative returns. L.M. Ericsson (+41.3%) and Altera
Corp. (+56.4%) both benefited from increased investment in wireless network
infrastructure. Biogen Idec (+55.7%) rose as investors reacted favorably to
positive data for its potential oral therapy for multiple sclerosis. Other top
contributors included Texas Instruments (+21.0%), Marsh & McLennan (+23.0%), and
Range Resources (+51.2%).

On the negative side, major detractors included Schweitzer-Mauduit
International, Southwest Airlines, and Research in Motion. Schweitzer-Mauduit
International (-18.8%), a supplier of reconstituted tobacco and paper used in
cigarettes, declined as European competitors challenged its patents for its
proprietary low ignition tobacco paper. We believe demand for low ignition paper
will expand rapidly as cigarette manufacturers around the world seek to meet
emerging safety regulations. Southwest Airlines (-14.5%), along with other
airlines, faced higher fuel costs as a consequence of political unrest in the
Middle East. Yet, Southwest has continued to expand its market share, especially
in new markets such as Denver and Boston, while maintaining its position as one
of the lowest cost airlines in the U.S. We view Southwest's recent acquisition
of AirTran Airways as a unique opportunity to accelerate the growth of its
network into many new markets including Atlanta, the world's busiest airport.
Research in Motion (-14.5%), maker of Blackberry smartphones and the new
Blackberry Playbook tablet computer, has struggled as investors focus on its
declining market share in North America relative to Apple's iPhone and phones
based on the Android operating system. However, the company has continued to
enjoy rapid growth in international markets, which now contribute the majority
of the company's revenues. Additionally, we expect the company's aging product
portfolio to be significantly refreshed over the coming months.

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
CONTINUED

The top 10 holdings, which collectively represent 34.4% of the portfolio at the
period end, are listed below:

--------------------------------------------------------------------------------
PRIMECAP ODYSSEY STOCK FUND ENDING % OF
TOP 10 HOLDINGS AS OF 4/30/11 TOTAL PORTFOLIO*
--------------------------------------------------------------------------------
Roche Holding AG 4.9

Amgen Inc. 4.2

Johnson & Johnson 3.7

Texas Instruments Inc. 3.5

Medtronic Inc. 3.5

L.M. Ericsson (ADR) 3.2

Marsh & McLennan Cos. 3.0

Eli Lilly & Co. 2.8

Novartis AG (ADR) 2.8

Microsoft Corp. 2.8
--------------------------------------------------------------------------------
TOTAL % OF PORTFOLIO 34.4%
--------------------------------------------------------------------------------

* The percentage is calculated by using the ending market value of the security
divided by the total investments of the Fund.

PRIMECAP Odyssey Growth Fund

From November 1, 2010 to April 30, 2011, the Growth Fund's total return was
+17.39%, which exceeded both the S&P 500's total return of +16.36% and the
Russell 1000 Growth Index's total return of +16.96%. Positive stock selection in
the health care and information technology sectors was a major contributor to
the fund's results. The fund also benefited from underweight positions in the
consumer staples, financials, and utilities sectors. This was offset by an
underweight position in the energy sector.

ImmunoGen (+62.5%), Cepheid (+53.6%), and Biogen Idec (+55.7%) were three health
care stocks that helped the fund's relative results. ImmunoGen, the fund's
largest holding, is a biotechnology company focused on developing targeted
anti-cancer therapies using its expertise in conjugated monoclonal antibodies.
Its stock rose on the release of positive clinical data for TDM-1, an antibody
drug conjugate that is being developed by a partner as a possible treatment for
some forms of metastatic breast cancer. Cepheid benefited from increasing market
acceptance of its molecular diagnostic systems. For example, the World Health
Organization recently endorsed the company's point of care tuberculosis test.

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
CONTINUED

Among information technology stocks, Altera (+56.4%) and Stratasys (+71.9%) were
large contributors to the fund's returns. Stratasys, a maker of 3-D printers
used for rapid prototyping and manufacturing of plastic parts, has continued to
see strong growth in sales as Hewlett-Packard (HP) has ramped up its efforts to
resell Stratasys' products under the HP brand.

Nektar Therapeutics (-28.8%) was one of the largest detractors from the fund's
results due to a dilutive equity offering following management's failure to find
a partner for its lead oncology drug candidate. As a result, the company will
now take on greater financial risk to fund trials for the drug, but it also
stands to potentially gain greater rewards if the drug is successful. Google
(-11.3%), AMR Corp (-25.6%), and Southwest Airlines (-14.5%) also hurt the
fund's returns.

The top 10 holdings, which collectively represent 27.9% of the portfolio at the
period end, are listed below:

--------------------------------------------------------------------------------
PRIMECAP ODYSSEY GROWTH FUND ENDING % OF
TOP 10 HOLDINGS AS OF 4/30/11 TOTAL PORTFOLIO*
--------------------------------------------------------------------------------

ImmunoGen Inc. 3.8

Roche Holding AG 3.7

Seattle Genetics Inc. 3.5

Amgen Inc. 3.4

Dendreon Corp. 2.8

Altera Corp. 2.6

Biogen Idec Inc. 2.2

Cepheid Inc. 2.2

Stratasys Inc. 1.9

Medtronic Inc. 1.8
--------------------------------------------------------------------------------
TOTAL % OF PORTFOLIO 27.9%
--------------------------------------------------------------------------------

* The percentage is calculated by using the ending market value of the security
divided by the total investments of the Fund.

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
CONTINUED

PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND

From November 1, 2010 to April 30, 2011, the Aggressive Growth Fund's total
return was +20.00%, ahead of the S&P 500's total return of +16.36% but behind
the Russell Midcap Growth Index's total return of +22.62%. Positive stock
selection in the information technology and health care sectors was the largest
contributor to relative returns, partially offset by the fund's underweight
position in the energy sector and poor stock selection in the consumer
discretionary and industrials sectors.

ImmunoGen (+62.5%), Cepheid (+53.6%), and InterMune (+239.2%) were among the
health care stocks with the highest returns in the portfolio. InterMune stock
rose on the news that its drug to treat idiopathic pulmonary fibrosis (IPF) had
received regulatory approval in Europe. This is the same drug that had been
rejected in the U.S. by the FDA in 2010. Stratasys (+71.9%), Altera Corp
(+56.4%), and GSI Commerce (+56.8%) were among the information technology stocks
with the highest returns. GSI Commerce, an e-commerce company specializing in
creating, developing, and running online shopping sites for retailers, announced
in March that it was being acquired for a substantial premium.

On the negative side, Nektar Therapeutics (-28.8%), DreamWorks Animation
(-25.0%), and AMR Corp (-25.6%) were among the biggest detractors from the
fund's returns. DreamWorks Animation struggled with weaker than expected box
office and home video sales. However, as a leading creator of animated films,
DreamWorks appears well-positioned to capitalize on its ability to create new
animated film franchises as well as to build upon existing ones.

LETTER TO SHAREHOLDERS
PRIMECAP Odyssey Funds
--------------------------------------------------------------------------------
CONTINUED

The top 10 holdings, which collectively represent 31.6% of the portfolio at the
period end, are listed below:

--------------------------------------------------------------------------------
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND ENDING % OF
TOP 10 HOLDINGS AS OF 4/30/11 TOTAL PORTFOLIO*
--------------------------------------------------------------------------------

Roche Holding AG 4.4

Seattle Genetics Inc. 3.9

Dendreon Corp. 3.9

ImmunoGen 3.8

Cepheid Inc. 3.3

Stratasys Inc. 3.0

Websense Inc. 2.4

Altera Corp. 2.4

Abiomed Inc. 2.3

Conceptus Inc. 2.2

--------------------------------------------------------------------------------
Total % of Portfolio 31.6%
--------------------------------------------------------------------------------

* The percentage is calculated by using the ending market value of the security
divided by the total investments of the Fund.

OUTLOOK

After seven consecutive quarters of increasing GDP and industrial production, it
is fair to say that the economic recovery is well underway. Stocks have
responded accordingly. The S&P 500 has roughly doubled from the lowest level
reached in March 2009 at the depths of the financial crisis. Smaller
capitalization stock indexes like the Russell 2000 have achieved even greater
returns.

Although the economic recovery has continued, its sustainability, in our
judgment, is not without risk. Labor and housing markets remain weak, the dollar
has depreciated relative to many major currencies, and surging commodity prices
fan fears of inflation and reduce consumer purchasing power. Additionally,
balancing budgets at the federal, state, and local government levels will
require austerity measures that may depress economic growth.

LETTER TO SHAREHOLDERS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
CONTINUED

Given the very strong recent gains posted by stocks and our more tempered
economic outlook, we are at the margin more cautious on stocks than we were at
the beginning of the year. We still find valuations reasonably attractive,
particularly relative to bonds and cash. Many companies in which the funds are
invested have been experiencing rapid growth in revenues and earnings, having
recovered from the recession with more efficient operations and stronger balance
sheets. We remain optimistic that innovation and global expansion should fuel
growth, especially for information technology and health care companies, two
sectors in which the funds have substantial investment and the United States has
a strong competitive advantage.

Sincerely,

PRIMECAP Management Company
May 19, 2011

--------------------------------------------------------------------------------
PAST PERFORMANCE IS NOT A GUARANTEE OF FUTURE RESULTS.

THE FUNDS INVEST IN SMALLER COMPANIES, WHICH INVOLVE ADDITIONAL RISKS SUCH AS
LIMITED LIQUIDITY AND GREATER VOLATILITY. ALL FUNDS MAY INVEST IN FOREIGN
SECURITIES, WHICH INVOLVES GREATER VOLATILITY AND POLITICAL, ECONOMIC AND
CURRENCY RISKS AND DIFFERENCES IN ACCOUNTING METHODS. MUTUAL FUND INVESTING
INVOLVES RISK, AND LOSS OF PRINCIPAL IS POSSIBLE. GROWTH STOCKS TYPICALLY ARE
MORE VOLATILE THAN VALUE STOCKS; HOWEVER, VALUE STOCKS HAVE A LOWER EXPECTED
GROWTH RATE IN EARNINGS AND SALES.

Please refer to the Schedule of Investments for details of fund holdings. Fund
holdings and sector allocations are subject to change at any time and are not
recommendations to buy or sell any security.

The S&P 500 INDEX is a broad based index of 500 stocks, which is widely
recognized as representative of the market in general. THE RUSSELL 1000 GROWTH
INDEX is an index that measures the performance of those Russell 1000 companies
with higher price-to-book ratios and higher forecasted growth values. THE
RUSSELL MID CAP GROWTH INDEX measures the performance of those Russell Mid Cap
companies with higher price-to-book ratios and higher forecasted growth values.
The Russell 2000 Index consists of the smallest 2,000 companies in a group of
3,000 U.S. companies in the Russell 3000 Index, as ranked by market
capitalization. These indices do not incur expenses and are not available for
investment.

Earnings growth is an indicator for measuring a company's success and can be the
driving force behind stock price appreciation.

THE INFORMATION PROVIDED HEREIN REPRESENTS THE OPINIONS OF PRIMECAP MANAGEMENT
COMPANY AND IS NOT INTENDED TO BE A FORECAST OF FUTURE EVENTS, A GUARANTEE OF
FUTURE RESULTS, OR INVESTMENT ADVICE.

PERFORMANCE GRAPHS
PRIMECAP ODYSSEY STOCK FUND
----------------------------------------------------------------

The following chart compares the value of a hypothetical $10,000 investment in
the PRIMECAP Odyssey Stock Fund from November 1, 2004 (inception) to April 30,
2011, compared to the S&P 500 Index. This chart illustrates the performance of a
hypothetical $10,000 investment made on the fund's inception date and is not
intended to imply any future performance. The returns shown do not reflect the
deduction of taxes that a shareholder would pay on fund distributions or the
redemption of fund shares. The chart assumes reinvestment of capital gains and
dividends.

CHART OMITTED

PRIMECAP ODYSSEY S&P 500
STOCK FUND INDEX
--------------------------------------------------------------------------------
11/1/04 $10,000 $10,000
4/30/05 10,490 10,324
10/31/05 11,480 10,868
4/30/06 13,047 11,914
10/31/06 13,487 12,643
1/31/07 14,632 13,729
10/31/07 15,359 14,483
4/30/08 13,799 13,088
10/31/08 10,332 9,256
4/30/09 10,095 8,465
10/31/09 12,042 10,161
4/30/10 14,110 11,752
10/31/10 13,986 11,839
4/30/11 16,185 13,775

TOTAL RETURN
PERIOD ENDED APRIL 30, 2011
---------------------------

ANNUALIZED
SINCE INCEPTION
1 YEAR 5 YEAR (11/01/04)
------ ------ ---------------

PRIMECAP Odyssey Stock Fund 14.70% 4.40% 7.70%

S&P 500 Index* 17.22% 2.95% 5.06%

--------
* The S&P 500 Index is an unmanaged index composed of 500 common stocks
weighted by market value; its total return includes reinvestment of
dividends and is considered representative of the stock market return as a
whole.

PERFORMANCE GRAPHS
PRIMECAP ODYSSEY GROWTH FUND
----------------------------------------------------------------

The following chart compares the value of a hypothetical $10,000 investment in
the PRIMECAP Odyssey Growth Fund from November 1, 2004 (inception) to April 30,
2011, compared to the S&P 500 Index. This chart illustrates the performance of a
hypothetical $10,000 investment made on the fund's inception date and is not
intended to imply any future performance. The returns shown do not reflect the
deduction of taxes that a shareholder would pay on fund distributions or the
redemption of fund shares. The chart assumes reinvestment of capital gains and
dividends.

CHART OMITTED

PRIMECAP ODYSSEY S&P 500
GROWTH FUND INDEX
--------------------------------------------------------------------------------
11/1/04 $10,000 $10,000
4/30/05 10,450 10,324
10/31/05 11,620 10,868
4/30/06 13,208 11,914
10/31/06 13,769 12,643
1/31/07 14,845 13,729
10/31/07 15,898 14,483
4/30/08 13,919 13,088
10/31/08 10,246 9,256
4/30/09 10,262 8,465
10/31/09 12,437 10,161
4/30/10 14,901 11,752
10/31/10 15,044 11,839
4/30/11 17,659 13,775

TOTAL RETURN
PERIOD ENDED APRIL 30, 2011
---------------------------

ANNUALIZED
SINCE INCEPTION
1 YEAR 5 YEAR (11/01/04)
------ ------ ---------------

PRIMECAP Odyssey Growth Fund 18.51% 5.98% 9.15%

S&P 500 Index* 17.22% 2.95% 5.06%

PERFORMANCE DATA QUOTED REPRESENTS PAST PERFORMANCE AND DOES NOT GUARANTEE
FUTURE RESULTS. THE INVESTMENT RETURN AND PRINCIPAL VALUE OF AN INVESTMENT WILL
FLUCTUATE SO THAT AN INVESTOR'S SHARES, WHEN REDEEMED, MAY BE WORTH MORE OR LESS
THAN THEIR ORIGINAL COST. CURRENT PERFORMANCE OF THE FUND MAY BE LOWER OR HIGHER
THAN THE PERFORMANCE QUOTED. PERFORMANCE DATA CURRENT TO THE MOST RECENT MONTH
END MAY BE OBTAINED BY CALLING 1-800-729-2307. THE FUND IMPOSES A 2% REDEMPTION
FEE ON SHARES HELD LESS THAN 60 DAYS.

PERFORMANCE GRAPHS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
----------------------------------------------------------------

The following chart compares the value of a hypothetical $10,000 investment in
the PRIMECAP Odyssey Aggressive Growth Fund from November 1, 2004 (inception) to
April 30, 2011, compared to the S&P 500 Index. This chart illustrates the
performance of a hypothetical $10,000 investment made on the fund's inception
date and is not intended to imply any future performance. The returns shown do
not reflect the deduction of taxes that a shareholder would pay on fund
distributions or the redemption of fund shares. The chart assumes reinvestment
of capital gains and dividends.

CHART OMITTED

PRIMECAP ODYSSEY S&P 500
GROWTH FUND INDEX
--------------------------------------------------------------------------------
11/1/04 $10,000 $10,000
4/30/05 9,890 10,324
10/31/05 11,240 10,868
4/30/06 13,110 11,914
10/31/06 13,920 12,643
1/31/07 15,280 13,729
10/31/07 16,253 14,483
4/30/08 13,134 13,088
10/31/08 9,654 9,256
4/30/09 10,113 8,465
10/31/09 12,583 10,161
4/30/10 16,185 11,752
10/31/10 16,501 11,839
4/30/11 19,801 13,775

TOTAL RETURN
PERIOD ENDED APRIL 30, 2011
---------------------------

ANNUALIZED
SINCE INCEPTION
1 YEAR 5 YEAR (11/01/04)
------ ------ ---------------
PRIMECAP Odyssey Aggressive
Growth Fund 22.34% 8.60% 11.09%

S&P 500 Index* 17.22% 2.95% 5.06%

EXPENSE EXAMPLE
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------
(UNAUDITED)

As a shareholder of one or more of the funds, you incur ongoing costs, including
management fees and other fund expenses. This expense example is intended to
help you understand your ongoing costs (in dollars) of investing in the funds
and to compare these costs with the ongoing costs of investing in other mutual
funds.

The expense example is based on an investment of $1,000 invested for a six month
period beginning November 1, 2010 and held through April 30, 2011.

ACTUAL EXPENSES

The information in the table adjacent to the heading "Actual Performance"
provides actual account values and actual expenses. You may use the information
in these columns, together with the amount you invested, to estimate the
expenses that you paid over the period. Simply divide your account value by
$1,000 (for example, an $8,600 account value divided by $1,000 = 8.6), then
multiply the result by the number in the column entitled "Expenses Paid during
Period" to estimate the expenses you paid on your account during this period.

HYPOTHETICAL EXAMPLE FOR COMPARISON PURPOSES

The information in the table adjacent to the heading "Hypothetical Performance
(5% return before expenses)" provides hypothetical account values and
hypothetical expenses based on the funds' actual expense ratios and an assumed
rate of return of 5% per year before expenses, which are not the funds' actual
returns. The hypothetical account values and expenses may not be used to
estimate the actual ending account balance or expenses you paid for the period.
You may use this information to compare the ongoing costs of investing in the
funds and other mutual funds. To do so, compare these 5% hypothetical examples
with the 5% hypothetical examples that appear in the shareholder reports of the
other mutual funds.

Please note that the expenses shown in the table are meant to highlight your
ongoing costs only. Therefore, the information adjacent to the heading
"Hypothetical Performance (5% return before expenses)" is useful in comparing
ongoing costs only and will not help you determine the relative total costs of
owning different mutual funds. In addition, if transactional costs were
included, your costs would have been higher.

EXPENSE EXAMPLE
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
(UNAUDITED) - CONTINUED

BEGINNING ENDING EXPENSES PAID EXPENSE RATIO
ACCOUNT ACCOUNT DURING PERIOD* DURING PERIOD*
VALUE VALUE (11/1/10 TO (11/1/10 TO
(11/1/10) (04/30/11) 04/30/11) 04/30/11)
--------------------------------------------------------------------------------
PRIMECAP ODYSSEY STOCK FUND

Actual Performance $1,000.00 $1,157.20 $3.50 0.65%
Hypothetical Performance
(5% return before
expenses) $1,000.00 $1,021.55 $3.28 0.65%
--------------------------------------------------------------------------------
PRIMECAP ODYSSEY GROWTH FUND

Actual Performance $1,000.00 $1,173.90 $3.54 0.66%
Hypothetical Performance
(5% return before
expenses) $1,000.00 $1,021.54 $3.29 0.66%
--------------------------------------------------------------------------------
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND

Actual Performance $1,000.00 $1,200.00 $3.69 0.68%
Hypothetical Performance
(5% return before
expenses) $1,000.00 $1,021.44 $3.39 0.68%
--------------------------------------------------------------------------------

--------
* Expenses are equal to a fund's annualized expense ratio as indicated,
multiplied by the average account value over the period, multiplied by the
number of days in the most recent fiscal half-year period (181), then
divided by the number of days in the fiscal year (365) to reflect the
one-half year period.

SECTOR BREAKDOWN
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------

PRIMECAP ODYSSEY STOCK FUND
----------------------------------------------------------------
Consumer Discretionary 8.6%

Consumer Staples 2.5%

Energy 9.7%

Financials 4.9%

Health Care 26.8%

Industrials 14.4%

Information Technology 23.2%

Materials 6.5%

Telecommunication Services 0.0%

Utilities 1.4%

Short Term Investments and Other Net Assets 2.0%
================================================================
TOTAL 100.0%
----------------------------------------------------------------

PRIMECAP ODYSSEY GROWTH FUND
----------------------------------------------------------------
Consumer Discretionary 7.0%

Consumer Staples 0.3%

Energy 6.7%

Financials 3.3%

Health Care 36.8%

Industrials 9.4%

Information Technology 29.2%

Materials 2.9%

Telecommunication Services 0.1%

Short Term Investments and Other Net Assets 4.3%
================================================================
TOTAL 100.0%
----------------------------------------------------------------

The tables above list sector allocations as a percentage of each fund's total
net assets as of April 30, 2011. The management report makes reference to
average allocations during the period. As a result, the sector allocations above
may differ from those discussed in the management report.

SECTOR BREAKDOWN
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
CONTINUED

PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
----------------------------------------------------------------
Consumer Discretionary 4.7%

Consumer Staples 1.4%

Energy 4.4%

Financials 1.3%

Health Care 38.8%

Industrials 9.1%

Information Technology 33.1%

Materials 2.6%

Telecommunication Services 0.1%

Short Term Investments and Other Net Assets 4.5%
================================================================
TOTAL 100.0%
----------------------------------------------------------------

The table above lists sector allocations as a percentage of the fund's total net
assets as of April 30, 2011. The management report makes reference to average
allocations during the period. As a result, the sector allocations above may
differ from those discussed in the management report.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY STOCK FUND
----------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)

Shares Value
--------------------------------------------------------------------------------
COMMON STOCKS - 98.0%

CONSUMER DISCRETIONARY - 8.6%
21,000 Amazon.com, Inc. (a) ....................... $ 4,126,500
188,700 Ascena Retail Group, Inc. (a) .............. 5,904,423
102,600 Bed Bath & Beyond, Inc. (a) ................ 5,757,912
200,900 CarMax, Inc. (a) ........................... 6,971,230
170,400 Collective Brands, Inc. (a) ................ 3,578,400
64,500 DIRECTV Group, Inc. (The) (a) .............. 3,134,055
32,200 Kohl's Corp. ............................... 1,697,262
50,000 Limited Brands, Inc. ....................... 2,058,000
200,000 Mattel, Inc. ............................... 5,344,000
8,100 Men's Wearhouse, Inc. ...................... 225,909
59,900 Sony Corp.- ADR ............................ 1,695,769
96,700 TJX Cos, Inc. .............................. 5,185,054
105,000 Walt Disney Co. (The) ...................... 4,525,500
212,500 Whirlpool Corp. ............................ 18,313,250
-----------
68,517,264
-----------

CONSUMER STAPLES - 2.5%
190,000 Kellogg Co. ................................ 10,881,300
60,000 PepsiCo, Inc. .............................. 4,133,400
80,000 Procter & Gamble Co. ....................... 5,192,000
-----------
20,206,700
-----------

ENERGY - 9.7%
100,000 Cameco Corp. ............................... 2,948,000
85,200 Cameron International Corp. (a) ............ 4,491,744
120,000 Cenovus Energy, Inc. ....................... 4,608,000
67,900 EOG Resources, Inc. ........................ 7,666,589
56,800 Hess Corp. ................................. 4,882,528
302,900 McDermott International, Inc. (a) .......... 6,993,961
94,700 National Oilwell Varco, Inc. ............... 7,262,543
50,000 Noble Energy, Inc. ......................... 4,813,500
304,000 Petroleo Brasileiro SA - ADR ............... 10,144,480
208,300 Range Resources Corp. ...................... 11,758,535
91,034 Schlumberger Ltd. .......................... 8,170,302
53,000 Transocean Ltd. (a) ........................ 3,855,750
-----------
77,595,932
-----------

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY STOCK FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--(CONTINUED)

Shares Value
--------------------------------------------------------------------------------
FINANCIALS - 4.9%
79,000 Charles Schwab Corp. (The) ................. $ 1,446,490
80,000 Chubb Corp. ................................ 5,215,200
111,100 Discover Financial Services ................ 2,759,724
799,600 Marsh & McLennan Cos., Inc. ................ 24,211,888
135,600 Mercury General Corp. ...................... 5,388,744
-----------
39,022,046
-----------

HEALTH CARE - 26.8%
8,000 Abbott Laboratories ........................ 416,320
75,000 Affymetrix, Inc. (a) ....................... 405,000
592,400 Amgen, Inc. (a) ............................ 33,677,940
158,500 Biogen Idec, Inc. (a) ...................... 15,429,975
227,900 Boston Scientific Corp. (a) ................ 1,706,971
611,000 Eli Lilly & Co. ............................ 22,613,110
473,935 GlaxoSmithKline PLC - ADR .................. 20,692,002
447,700 Johnson & Johnson .......................... 29,422,844
668,000 Medtronic, Inc. ............................ 27,889,000
378,950 Novartis AG - ADR .......................... 22,422,471
237,716 Roche Holding AG - CHF ..................... 38,556,711
-----------
213,232,344
-----------

INDUSTRIALS - 14.4%
23,800 Alaska Air Group, Inc. (a) ................. 1,567,706
10,000 Alexander & Baldwin, Inc. .................. 527,000
160,100 AMR Corp. (a) .............................. 939,787
244,900 Arkansas Best Corp. ........................ 5,635,149
459,700 Babcock & Wilcox Co. (a) ................... 14,439,177
201,400 Boeing Co. ................................. 16,067,692
50,000 Canadian Pacific Railway Ltd. .............. 3,312,000
8,300 Caterpillar, Inc. .......................... 957,903
10,000 Deere & Co. ................................ 975,000
26,200 FedEx Corp. ................................ 2,506,554
201,900 Honeywell International, Inc. .............. 12,362,337
23,500 JetBlue Airways Corp. (a) .................. 133,010
140,000 Norfolk Southern Corp. ..................... 10,455,200
64,300 Pall Corp. ................................. 3,757,692
179,400 Ritchie Bros. Auctioneers, Inc. ............ 5,609,838
100,700 Rockwell Automation, Inc. .................. 8,773,991
1,039,200 Southwest Airlines Co. ..................... 12,210,600
1,900 Thomas & Betts Corp. (a) ................... 110,143

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY STOCK FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--(CONTINUED)

Shares Value
--------------------------------------------------------------------------------
INDUSTRIALS (CONTINUED)
36,000 Union Pacific Corp. ........................ $ 3,724,920
140,000 United Parcel Service, Inc. - Class B ...... 10,495,800
-----------
114,561,499
-----------

INFORMATION TECHNOLOGY - 23.2%
45,650 Accenture Ltd. - Class A ................... 2,607,984
237,200 Altera Corp. ............................... 11,551,640
268,700 Applied Materials, Inc. .................... 4,215,903
24,577 ASML Holding N.V. - ADR .................... 1,026,336
200,000 Corning, Inc. .............................. 4,188,000
100,000 Diebold, Inc. .............................. 3,380,000
416,400 Electronic Arts, Inc. (a) .................. 8,402,952
204,600 EMC Corp. (a) .............................. 5,798,364
4,900 Google, Inc. - Class A (a) ................. 2,666,090
46,000 Hewlett-Packard Co. ........................ 1,857,020
260,000 Intel Corp. ................................ 6,029,400
94,700 Intuit, Inc. (a) ........................... 5,261,532
302,600 KLA-Tencor Corp. ........................... 13,284,140
1,664,700 L.M. Ericsson Telephone Co. - ADR .......... 25,303,440
838,700 Microsoft Corp. ............................ 21,822,974
14,112 Motorola Mobility Holdings, Inc. (a) ....... 367,759
16,128 Motorola Solutions, Inc. (a) ............... 739,952
81,400 NeuStar, Inc. - Class A (a) ................ 2,188,846
284,000 NVIDIA Corp. (a) ........................... 5,680,000
50,700 Oracle Corp. ............................... 1,827,735
45,900 QUALCOMM, Inc. ............................. 2,608,956
212,600 Research In Motion Ltd. (a) ................ 10,342,990
225,800 Symantec Corp. (a) ......................... 4,436,970
787,800 Texas Instruments, Inc. .................... 27,990,534
90,000 Visa, Inc. - Class A ....................... 7,030,800
100,000 Xilinx, Inc. ............................... 3,486,000
24,800 Yahoo!, Inc. (a) ........................... 440,200
-----------
184,536,517
-----------

MATERIALS - 6.5%
113,600 Freeport-McMoRan Copper & Gold, Inc. ....... 6,251,408
71,900 Monsanto Co. ............................... 4,892,076
44,100 Newmont Mining Corp. ....................... 2,584,701

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY STOCK FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--(CONTINUED)

Shares Value
--------------------------------------------------------------------------------
MATERIALS (CONTINUED)
159,500 Potash Corp. of Saskatchewan, Inc. ......... $ 8,992,610
298,500 Schweitzer-Mauduit International, Inc. ..... 15,474,240
309,293 Vulcan Materials Co. ....................... 13,980,044
-----------
52,175,079
-----------
TELECOMMUNICATION SERVICES - 0.0%
56,600 Sprint Nextel Corp. (a) .................... 293,188
-----------

UTILITIES -1.4%
80,000 Edison International ....................... 3,141,600
50,000 NextEra Energy, Inc. ....................... 2,828,500
152,600 Public Service Enterprise Group, Inc. ...... 4,909,142
-----------
10,879,242
-----------
TOTAL COMMON STOCKS
(Cost $627,809,331) .................................... $ 781,019,811
-------------

SHORT TERM INVESTMENTS - 1.8%
14,606,275 Dreyfus Treasury Prime Cash Management Fund $ 14,606,275
------------

TOTAL SHORT TERM INVESTMENTS
(Cost $14,606,275) ..................................... 14,606,275
------------

TOTAL INVESTMENTS - 99.8%
(Cost $642,415,606) .................................... 795,626,086
Other Assets in Excess of Liabilities - 0.2% ............ 1,525,370
------------
TOTAL NET ASSETS - 100.0% ............................... $797,151,456
============

--------
Percentages are stated as a percent of net assets.
ADR - American Depository Receipt.
CHF - Swiss Franc.
(a) Non-Income Producing.

The Global Industry Classification Standard (GICS (R)) was developed by and is
the exclusive property of MSCI Inc. and Standard & Poor's Financial Services LLC
("S&P"). GICS is a service mark of MSCI and S&P and has been licensed for use by
PRIMECAP Management Company.

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY GROWTH FUND
----------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)

Shares Value
--------------------------------------------------------------------------------

COMMON STOCKS - 95.7%

CONSUMER DISCRETIONARY - 7.0%
250,000 99 Cents Only Stores (a) ................... $ 5,040,000
77,900 Amazon.com, Inc. (a) ....................... 15,307,350
357,900 Ascena Retail Group, Inc. (a) .............. 11,198,691
275,600 Bed Bath & Beyond, Inc. (a) ................ 15,466,672
717,000 CarMax, Inc. (a) ........................... 24,879,900
80,000 Carnival Corp. ............................. 3,045,600
166,200 DIRECTV Group, Inc. (The) (a) .............. 8,075,658
752,000 DreamWorks Animation SKG, Inc. (a) ......... 19,920,480
228,500 Gentex Corp. . ............................. 7,163,475
55,850 Kohl's Corp................................. 2,943,854
100,000 Limited Brands, Inc......................... 4,116,000
400,000 Mattel, Inc................................. 10,688,000
182,300 Quiksilver, Inc. (a) ....................... 793,005
252,100 Sony Corp. - ADR ........................... 7,136,951
63,000 TJX Cos, Inc................................ 3,378,060
--------------
139,153,696
--------------

CONSUMER STAPLES - 0.3%
100,000 Procter & Gamble Co. ....................... 6,490,000
--------------

ENERGY - 6.7%
140,000 Cenovus Energy, Inc. ....................... 5,376,000
104,400 EnCana Corp. ............................... 3,499,488
140,000 EOG Resources, Inc. ........................ 15,807,400
120,000 Hess Corp. ................................. 10,315,200
300,000 McDermott International, Inc. (a) .......... 6,927,000
180,000 National Oilwell Varco, Inc. ............... 13,804,200
80,000 Noble Energy, Inc. ......................... 7,701,600
170,000 Oceaneering International, Inc. (a) ........ 14,861,400
187,900 Petroleo Brasileiro SA - ADR ............... 6,270,223
340,000 Range Resources Corp. ...................... 19,193,000
173,100 Schlumberger Ltd. .......................... 15,535,725
300,000 Southwestern Energy Co. (a) ................ 13,158,000
--------------
132,449,236
--------------

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
FINANCIALS - 3.3%
533,900 Charles Schwab Corp. (The) ................. $ 9,775,709
100,000 Berkshire Hathaway, Inc. - Class B (a) ..... 8,330,000
180,000 Chubb Corp. ................................ 11,734,200
1,045,700 Marsh & McLennan Cos., Inc. ................ 31,663,796
140,000 Progressive Corp. (The) .................... 3,071,600
--------------
64,575,305
--------------

HEALTH CARE - 36.8%
850,000 Abiomed, Inc. (a) .......................... 14,773,000
2,705,000 Accuray, Inc. (a) .......................... 24,047,450
199,400 Affymetrix, Inc. (a) ....................... 1,076,760
1,193,300 Amgen, Inc. (a) ............................ 67,839,105
451,500 Biogen Idec, Inc. (a) ...................... 43,953,525
298,200 BioMarin Pharmaceutical, Inc. (a) .......... 8,018,598
672,500 Boston Scientific Corp. (a) ................ 5,037,025
1,340,100 Cepheid, Inc. (a) .......................... 43,298,631
40,000 Cerner Corp. (a) ........................... 4,807,200
2,253,728 Conceptus, Inc. (a) (b) .................... 34,775,023
1,271,500 Dendreon Corp. (a) ......................... 55,221,245
787,200 Eli Lilly & Co. ............................ 29,134,272
88,800 GlaxoSmithKline PLC - ADR .................. 3,877,008
270,000 Illumina, Inc. (a) ......................... 19,164,600
5,620,000 ImmunoGen, Inc. (a) (b) .................... 75,083,200
270,000 Johnson & Johnson .......................... 17,744,400
200,000 Kinetic Concepts, Inc. (a) ................. 11,806,000
120,000 Life Technologies Corp. (a) ................ 6,624,000
872,300 Medtronic, Inc. ............................ 36,418,525
300,000 Momenta Pharmaceuticals, Inc. (a) .......... 5,661,000
2,930,600 Nektar Therapeutics (a) .................... 30,419,628
344,750 Novartis AG - ADR .......................... 20,398,858
145,000 NuVasive, Inc. (a) ......................... 4,479,050
260,000 OraSure Technologies, Inc. (a) ............. 2,290,600
457,632 Roche Holding AG - CHF ..................... 74,226,323
4,179,600 Seattle Genetics, Inc. (a) ................. 69,423,156
136,200 SurModics, Inc. (a) ........................ 2,092,032
168,500 Waters Corp. (a) ........................... 16,513,000
--------------
728,203,214
--------------
The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------

INDUSTRIALS - 9.4%
637,000 AECOM Technology Corp. (a) ................. $ 17,364,620
2,317,300 AMR Corp. (a) .............................. 13,602,551
680,000 Babcock & Wilcox Co. (a) ................... 21,358,800
300,000 C. H. Robinson Worldwide, Inc. ............. 24,054,000
133,600 Caterpillar, Inc. .......................... 15,418,776
187,565 Colfax Corp. (a) ........................... 4,098,295
320,000 Expeditors International Washington, Inc. .. 17,366,400
50,600 FedEx Corp. ................................ 4,840,902
850,150 JetBlue Airways Corp. (a) .................. 4,811,849
107,800 Pall Corp. ................................. 6,299,832
389,000 Ritchie Bros. Auctioneers, Inc. ............ 12,164,030
50,000 Rockwell Automation, Inc. .................. 4,356,500
2,376,600 Southwest Airlines Co. ..................... 27,925,050
182,100 United Parcel Service, Inc. - Class B ...... 13,652,037
--------------
187,313,642
--------------

INFORMATION TECHNOLOGY - 29.2%
57,850 Accenture Ltd. - Class A ................... 3,304,970
702,500 Adobe Systems, Inc. (a) .................... 23,568,875
200,000 Akamai Technologies, Inc. (a) .............. 6,888,000
1,040,000 Altera Corp. ............................... 50,648,000
389,300 Applied Materials, Inc. .................... 6,108,117
116,000 ASML Holding N.V. - ADR .................... 4,844,160
138,000 Avid Technology, Inc. (a) .................. 2,564,040
30,000 Cisco Systems, Inc. (a) .................... 526,800
198,800 Corning, Inc. .............................. 4,162,872
350,100 Cree, Inc. (a) ............................. 14,263,074
37,000 Cymer, Inc. (a) ............................ 1,780,070
1,752,000 Electronic Arts, Inc. (a) .................. 35,355,360
783,700 EMC Corp. (a) .............................. 22,210,058
2,160,000 Flextronics International Ltd. (a) ......... 15,055,200
833,450 FormFactor, Inc. (a) ....................... 8,642,877
62,580 Google, Inc. - Class A (a) ................. 34,049,778
530,000 GSI Commerce, Inc. (a) ..................... 15,513,100
90,000 Hewlett-Packard Co. ........................ 3,633,300
250,700 Intel Corp. ................................ 5,813,733
390,400 Intuit, Inc. (a) ........................... 21,690,624
331,300 KLA-Tencor Corp. ........................... 14,544,070
2,362,800 L.M. Ericsson Telephone Co. - ADR .......... 35,914,560
5,500 MasterCard, Inc. - Class A .................. 1,517,395

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
INFORMATION TECHNOLOGY (CONTINUED)
525,000 Micron Technology, Inc. (a) ................ $ 5,927,250
676,300 Microsoft Corp. ............................ 17,597,326
30,737 Motorola Mobility Holdings, Inc. (a) ....... 801,006
35,128 Motorola Solutions, Inc. (a) ............... 1,611,673
195,900 NeuStar, Inc. - Class A (a) ................ 5,267,751
1,530,000 Nuance Communications, Inc. (a) ............ 31,671,000
540,000 NVIDIA Corp. (a) ........................... 10,800,000
231,100 Oracle Corp. ............................... 8,331,155
90,000 QUALCOMM, Inc. ............................. 5,115,600
409,800 Rambus, Inc. (a) ........................... 8,155,020
598,850 Research In Motion Ltd. (a) ................ 29,134,052
151,800 SanDisk Corp. (a) .......................... 7,459,452
680,000 Stratasys, Inc. (a) ........................ 36,618,000
536,400 Symantec Corp. (a) ......................... 10,540,260
884,000 Texas Instruments, Inc. .................... 31,408,520
200,000 Trimble Navigation Ltd. (a) ................ 9,368,000
265,000 Visa, Inc. - Class A ....................... 20,701,800
120,000 Xilinx, Inc. ............................... 4,183,200
--------------
577,290,098
--------------

MATERIALS - 2.9%
470,900 Monsanto Co. ............................... 32,040,036
117,600 Potash Corp. of Saskatchewan, Inc. ......... 6,630,288
17,250 Praxair, Inc. .............................. 1,835,745
378,200 Vulcan Materials Co. ....................... 17,094,640
--------------
57,600,709
--------------

TELECOMMUNICATION SERVICES - 0.1%
292,450 Sprint Nextel Corp. (a) .................... 1,514,891
--------------

TOTAL COMMON STOCKS
(Cost $1,492,157,673) ................................. $1,894,590,791
--------------

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
SHORT TERM INVESTMENTS - 4.2%
83,064,411 Dreyfus Treasury Prime Cash Management Fund $ 83,064,411
--------------
TOTAL SHORT TERM INVESTMENTS
(Cost $83,064,411) ..................................... 83,064,411
--------------
TOTAL INVESTMENTS - 99.9%
(Cost $1,575,222,084) .................................. 1,977,655,202
Other Assets in Excess of Liabilities - 0.1% ............ 1,237,973
--------------
TOTAL NET ASSETS - 100.0% ............................... $1,978,893,175
==============

------
Percentages are stated as a percent of net assets.
ADR - American Depository Receipt.
CHF - Swiss Franc.
(a) Non-Income Producing.
(b) Considered an affiliated company of the fund as the fund owns more than 5%
of the outstanding voting securities of such company.

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
----------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
COMMON STOCKS - 95.5%

CONSUMER DISCRETIONARY - 4.7%
63,000 Amazon.com, Inc. (a) ....................... $ 12,379,500
2,000 Bravo Brio Restaurant Group, Inc. (a) ...... 41,280
333,400 CarMax, Inc. (a) ........................... 11,568,980
74,700 DIRECTV Group, Inc. (The) (a) .............. 3,629,673
828,300 DreamWorks Animation SKG, Inc. (a) ......... 21,941,667
140,000 Gentex Corp. ............................... 4,389,000
229,000 Quiksilver, Inc. (a) ....................... 996,150
--------------
54,946,250
--------------
CONSUMER STAPLES - 1.4%
3,413,405 Smart Balance, Inc. (a) (b) ................ 16,316,076
--------------

ENERGY - 4.4%
200,000 Cabot Oil & Gas Corp. ...................... 11,256,000
50,000 EOG Resources, Inc. ........................ 5,645,500
120,000 National Oilwell Varco, Inc. ............... 9,202,800
84,000 Oceaneering International, Inc. (a) ........ 7,343,280
200,000 Range Resources Corp. ...................... 11,290,000
520,000 Rex Energy Corp. (a) ....................... 6,671,600
--------------
51,409,180
--------------
FINANCIALS - 1.3%
605,820 MarketAxess Holdings, Inc. ................. 14,751,717
--------------

HEALTH CARE - 38.8%
1,533,373 Abiomed, Inc. (a) .......................... 26,650,023
2,330,000 Accuray, Inc. (a) .......................... 20,713,700
172,000 Affymetrix, Inc. (a) ....................... 928,800
205,000 Biogen Idec, Inc. (a) ...................... 19,956,750
590,300 BioMarin Pharmaceutical, Inc. (a) .......... 15,873,167
791,700 Boston Scientific Corp. (a) ................ 5,929,833
591,600 Cardica, Inc. (a) .......................... 2,342,736
1,172,800 Cepheid, Inc. (a) .......................... 37,893,168
1,669,750 Conceptus, Inc. (a) (b) .................... 25,764,242
1,031,800 Dendreon Corp. (a) ......................... 44,811,074
5,625,000 Dyax Corp. (a) (b) ......................... 11,250,000
3,330,250 ImmunoGen, Inc. (a) ........................ 44,492,140
360,000 InterMune, Inc. (a) ........................ 16,070,400
198,500 Kinetic Concepts, Inc. (a) ................. 11,717,455
706,200 Luminex Corp. (a) .......................... 13,693,218

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
HEALTH CARE (CONTINUED)
80,000 Momenta Pharmaceuticals, Inc. (a) .......... $ 1,509,600
1,932,000 Nektar Therapeutics (a) ................... 20,054,160
155,000 NuVasive, Inc. (a) ......................... 4,787,950
1,742,600 OraSure Technologies, Inc. (a) ............. 15,352,306
1,768,339 Pharmacyclics, Inc. (a) .................... 11,724,088
317,200 Roche Holding AG - CHF ..................... 51,448,740
2,747,300 Seattle Genetics, Inc. (a) ................. 45,632,653
116,000 SurModics, Inc. (a) ........................ 1,781,760
--------------
450,377,963
--------------

INDUSTRIALS - 9.1%
201,900 AECOM Technology Corp. (a) ................. 5,503,794
195,000 Alaska Air Group, Inc. (a) ................. 12,844,650
2,130,000 AMR Corp. (a) .............................. 12,503,100
433,700 Arkansas Best Corp. ........................ 9,979,437
140,000 C. H. Robinson Worldwide, Inc. ............. 11,225,200
441,210 Colfax Corp. (a) ........................... 9,640,438
2,224,525 JetBlue Airways Corp. (a) .................. 12,590,812
82,600 Pall Corp. ................................. 4,827,144
293,100 Ritchie Bros. Auctioneers, Inc. ............ 9,165,237
582,100 Southwest Airlines Co. ..................... 6,839,675
234,000 US Airways Group, Inc. (a) ................. 2,127,060
45,000 USA Truck, Inc. (a) ........................ 560,250
470,000 Vitran Corp, Inc. (a) ...................... 7,327,300
2,600 Zipcar, Inc. (a) ........................... 67,054
--------------
105,201,151
--------------

INFORMATION TECHNOLOGY - 33.1%
615,000 Adobe Systems, Inc. (a) .................... 20,633,250
180,000 Akamai Technologies, Inc. (a) .............. 6,199,200
570,000 Altera Corp. ............................... 27,759,000
247,777 ASML Holding N.V. - ADR .................... 10,347,167
115,000 Avid Technology, Inc. (a) .................. 2,136,700
273,500 Cree, Inc. (a) ............................. 11,142,390
96,500 Cymer, Inc. (a) ............................ 4,642,615
1,083,400 Electronic Arts, Inc. (a) .................. 21,863,012
200,000 EMC Corp. (a) .............................. 5,668,000
270,000 FARO Technologies, Inc. (a) ................ 11,655,900
240,000 FEI Co. (a) ................................ 7,790,400
716,300 FormFactor, Inc. (a) ....................... 7,428,031

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
INFORMATION TECHNOLOGY (CONTINUED)
36,600 Google, Inc. - Class A (a) ................. $ 19,914,060
812,000 GSI Commerce, Inc. (a) ..................... 23,767,240
1,087,100 Guidance Software, Inc. (a) ................ 8,685,929
275,000 Intuit, Inc. (a) ........................... 15,279,000
365,300 KLA-Tencor Corp. ........................... 16,036,670
800,000 Micron Technology, Inc. (a) ................ 9,032,000
420,000 Monster Worldwide, Inc. (a) ................ 6,892,200
149,200 NeuStar, Inc. - Class A (a) ................ 4,011,988
570,000 Nuance Communications, Inc. (a) ............ 11,799,000
326,550 NVIDIA Corp. (a) ........................... 6,531,000
311,800 Rambus, Inc. (a) ........................... 6,204,820
481,200 Research In Motion Ltd. (a) ................ 23,410,380
5,400 Responsys, Inc. (a) ........................ 86,292
260,000 RightNow Technologies, Inc. (a) ............ 9,406,800
83,100 SanDisk Corp. (a) .......................... 4,083,534
733,500 SMART Technologies, Inc. - Class A (a) ..... 7,305,660
637,700 Stratasys, Inc. (a) ........................ 34,340,145
230,100 Symantec Corp. (a) ......................... 4,521,465
120,000 Trimble Navigation Ltd. (a) ................ 5,620,800
1,104,600 Websense, Inc. (a) ......................... 28,487,634
60,000 Yahoo!, Inc. (a) ........................... 1,065,000
--------------
383,747,282
--------------

MATERIALS - 2.6%
306,800 Monsanto Co. . ............................. 20,874,672
63,200 Potash Corp. of Saskatchewan, Inc. ......... 9,201,216
--------------
30,075,888
--------------

TELECOMMUNICATION SERVICES - 0.1%
296,700 Sprint Nextel Corp. (a) .................... 1,536,906
--------------

TOTAL COMMON STOCKS
(Cost $852,312,143) .................................... $1,108,362,413
--------------

The accompanying notes are an integral part of these financial statements.

SCHEDULE OF INVESTMENTS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
--------------------------------------------------------------------------------
APRIL 30, 2011 (UNAUDITED)--CONTINUED

Shares Value
--------------------------------------------------------------------------------
SHORT TERM INVESTMENTS - 4.7%

54,159,249 Dreyfus Treasury Prime Cash Management Fund $ 54,159,249
--------------

TOTAL SHORT TERM INVESTMENTS
(Cost $54,159,249) ..................................... 54,159,249
--------------

TOTAL INVESTMENTS - 100.2%
(Cost $906,471,392) .................................... 1,162,521,662
Liabilities in Excess of Other Assets - (0.2)% .......... (2,504,522)
--------------

TOTAL NET ASSETS - 100.0% ............................... $1,160,017,140
==============
------
Percentages are stated as a percent of net assets.
ADR - American Depository Receipt.
CHF - Swiss Franc.
(a) Non-Income Producing.

(b) Considered an affiliated company of the fund as the fund owns more than 5%
of the outstanding voting securities of such company.

The accompanying notes are an integral part of these financial statements.

STATEMENTS OF ASSETS AND LIABILITIES
PRIMECAP ODYSSEY FUNDS
APRIL 30, 2011 (UNAUDITED)
-------------------------------------------------------------------------
PRIMECAP PRIMECAP PRIMECAP
ODYSSEY ODYSSEY ODYSSEY AGGRESSIVE
STOCK FUND GROWTH FUND GROWTH FUND
---------- ----------- ------------------
ASSETS
Investments, at cost ............... $642,415,606 $1,575,222,084 $ 906,471,392
============ ============== ==============

Investments, at value (unaffiliated) $795,626,086 $1,867,796,979 $1,109,191,344
Investments, at value (affiliated) -- 109,858,223 53,330,318
Receivables:
Securities sold ................... 1,530,067 5,606,545 1,280,723
Dividends and interest ............ 1,453,117 2,259,133 717,842
Fund shares sold .................. 964,781 3,704,574 3,098,456
Prepaid expenses and other assets 29,874 68,166 48,980
------------ -------------- --------------
Total assets ..................... 799,603,925 1,989,293,620 1,167,667,663
------------ -------------- --------------
LIABILITIES
Payable for securities purchased ... 878,187 7,035,137 5,333,245
Payable for fund shares repurchased 245,755 644,821 665,123
Payable to advisor (Note 6) ........ 1,172,663 2,455,013 1,430,031
Other accrued expenses & liabilities 155,864 265,474 222,124
------------ -------------- --------------
Total liabilities ................ 2,452,469 10,400,445 7,650,523
------------ -------------- --------------
NET ASSETS ........................... $797,151,456 $1,978,893,175 $1,160,017,140
============ ============== ==============
Number of shares issued and
outstanding (unlimited shares
authorized, $0.01 par value) ....... 51,508,727 114,756,407 61,741,037
============ ============== ==============
Net asset value, offering and
redemption price per share ......... $ 15.48 $ 17.24 $ 18.79
============ ============== ==============
COMPONENTS OF NET ASSETS
Paid-in capital .................... $666,524,804 $ 1,558,857,061 $ 888,885,988
Undistributed net
investment income ................. 4,692,079 3,360,021 --
Accumulated net realized
gain (loss) on
investments ....................... (27,329,387) 14,131,293 15,020,094
Accumulated net unrealized
appreciation on investments ........ 153,263,960 402,544,800 256,111,058
------------ -------------- --------------
Net assets ....................... $797,151,456 $1,978,893,175 $1,160,017,140
============ ============== ==============

The accompanying notes are an integral part of these financial statements.

STATEMENTS OF OPERATIONS
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED)

PRIMECAP
PRIMECAP PRIMECAP ODYSSEY
ODYSSEY ODYSSEY AGGRESSIVE
STOCK FUND GROWTH FUND GROWTH FUND
---------- ----------- -----------
INVESTMENT INCOME
Income
Dividends (net of foreign taxes
withheld of $527,635, $756,505,
and $344,207, respectively) ... $ 8,198,292 $ 9,239,844 $ 2,643,575
Interest income ................ 232 332 221
------------ ------------ ------------
Total income .................. 8,198,524 9,240,176 2,643,796
------------ ------------ ------------
Expenses
Advisory fees .................. 2,175,202 4,659,976 2,680,913
Fund administration and
accounting fees ............... 163,775 356,308 201,042
Professional fees .............. 27,349 27,738 27,388
Shareholder servicing fees ..... 81,440 276,725 200,050
Registration fees .............. 15,168 33,295 29,395
Custody fees ................... 36,550 68,100 44,660
Trustee fees ................... 14,430 14,599 14,399
Printing and mailing ........... 9,444 36,290 30,565
Other .......................... 33,859 56,906 36,825
------------ ------------ ------------
Total expenses ................ 2,557,217 5,529,937 3,265,237
------------ ------------ ------------

Net investment income (loss) 5,641,307 3,710,239 (621,441)
------------ ------------ ------------
REALIZED AND UNREALIZED
GAIN ON INVESTMENTS
Net realized gain on investments 5,469,786 28,600,036 15,097,101
------------ ------------ ------------
Change in net unrealized
appreciation on investments .... 99,906,734 244,879,598 167,701,156
------------ ------------ ------------
Net realized and unrealized gain
on investments ................. 105,376,520 273,479,634 182,798,257
------------ ------------ ------------
Net increase in net assets
resulting from operations .... $111,017,827 $277,189,873 $182,176,816
============ ============ ============

The accompanying notes are an integral part of these financial statements.

STATEMENT OF CHANGES IN NET ASSETS
PRIMECAP ODYSSEY STOCK FUND
----------------------------------------------------------------

SIX MONTHS
ENDED YEAR ENDED
APRIL 30, 2011(1) OCTOBER 31, 2010
-------------- ----------------
INCREASE IN NET ASSETS FROM:
OPERATIONS
Net investment income ................. $ 5,641,307 $ 4,596,688
Net realized gain on investments ...... 5,469,786 1,276,438
Change in net unrealized appreciation
on investments ....................... 99,906,734 52,908,147
------------- ------------
NET INCREASE IN NET ASSETS
RESULTING FROM OPERATIONS ........... 111,017,827 58,781,273
------------- ------------
DISTRIBUTIONS TO SHAREHOLDERS
FROM NET INVESTMENT INCOME .............. (5,099,941) (1,831,079)
------------- ------------
CAPITAL SHARE TRANSACTIONS
Proceeds from shares sold ............. 286,834,925 403,570,379
Proceeds from reinvestment
of distribution. ..................... 4,774,772 1,822,043
Cost of shares redeemed ............... (207,442,119) (34,962,948)
Redemption fee proceeds ............... 6,436 7,738
------------- ------------
NET INCREASE FROM CAPITAL
SHARE TRANSACTIONS ................... 84,174,014 370,437,212
------------- ------------

TOTAL INCREASE IN NET ASSETS .......... 190,091,900 427,387,406

NET ASSETS
Beginning of period ................... 607,059,556 179,672,150
------------- ------------
End of period (includes
undistributed net investment
income of $4,692,079 and
$4,150,713, respectively) ............ $ 797,151,456 $607,059,556
============= ============

CHANGE IN CAPITAL SHARES
Shares outstanding, beginning
of period ............................ 45,027,268 15,370,380
------------- ------------
Shares sold ........................... 20,128,907 32,259,418
Shares issued on reinvestment
of distributions ..................... 341,543 144,721
Shares repurchased .................... (13,988,991) (2,747,251)
------------- ------------
Net increase in capital shares ....... 6,481,459 29,656,888
------------- ------------
Shares outstanding, end of period .... 51,508,727 45,027,268
============= ============
------
(1) Unaudited.

The accompanying notes are an integral part of these financial statements.

STATEMENT OF CHANGES IN NET ASSETS
PRIMECAP ODYSSEY GROWTH FUND
----------------------------------------------------------------

SIX MONTHS
ENDED YEAR ENDED
APRIL 30, 2011(1) OCTOBER 31, 2010
-------------- ----------------
INCREASE IN NET ASSETS FROM:
OPERATIONS
Net investment income .................. $ 3,710,239 $ 1,633,753
Net realized gain on investments ....... 28,600,036 999,154
Change in net unrealized
appreciation on investments ........... 244,879,598 189,779,096
-------------- --------------
NET INCREASE IN NET ASSETS
RESULTING FROM OPERATIONS ............ 277,189,873 192,412,003
-------------- --------------
DISTRIBUTIONS TO SHAREHOLDERS
FROM NET INVESTMENT INCOME ............... (1,416,348) (1,825,837)
-------------- --------------
CAPITAL SHARE TRANSACTIONS
Proceeds from shares sold .............. 402,281,006 745,167,382
Proceeds from reinvestment
of distribution ....................... 1,337,875 1,740,542
Cost of shares redeemed ................ (151,707,813) (192,905,219)
Redemption fee proceeds ................ 42,676 87,258
-------------- --------------
NET INCREASE FROM CAPITAL SHARE
TRANSACTIONS ......................... 251,953,744 554,089,963
-------------- --------------

TOTAL INCREASE IN NET ASSETS .......... 527,727,269 744,676,129

NET ASSETS
Beginning of period .................... 1,451,165,906 706,489,777
-------------- --------------
End of period (including
undistributed net investment
income of $3,360,021 and
$1,066,130, respectively) ............. $1,978,893,175 $1,451,165,906
============== ==============

CHANGE IN CAPITAL SHARES
Shares outstanding, beginning of period 98,706,971 57,986,448
-------------- --------------
Shares sold ........................... 25,611,553 54,837,387
Shares issued on reinvestment
of distributions ..................... 87,787 132,764
Shares repurchased .................... (9,649,904) (14,249,628)
-------------- --------------
Net increase in capital shares ....... 16,049,436 40,720,523
-------------- --------------
Shares outstanding, end of period ...... 114,756,407 98,706,971
============== ==============
------
(1) Unaudited.

The accompanying notes are an integral part of these financial statements.

STATEMENT OF CHANGES IN NET ASSETS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
----------------------------------------------------------------

SIX MONTHS
ENDED YEAR ENDED
APRIL 30, 2011(1) OCTOBER 31, 2010
-------------- ----------------
INCREASE (DECREASE) IN NET ASSETS FROM:
OPERATIONS
Net investment loss ................ $ (621,441) $ (2,543,607)
Net realized gain on investments ... 15,097,101 41,684,298
Change in net unrealized
appreciation on investments ....... 167,701,156 102,743,903
-------------- ------------
Net increase in net assets
resulting from operations ........ 182,176,816 141,884,594
-------------- ------------
DISTRIBUTIONS TO SHAREHOLDERS
FROM REALIZED GAIN ON INVESTMENTS .... (27,881,437) --
-------------- ------------
CAPITAL SHARE TRANSACTIONS
Proceeds from shares sold .......... 248,488,498 402,604,235
Proceeds from reinvestment
of distribution ................... 27,335,474 --
Cost of shares redeemed ............ (80,084,741) (98,500,526)
Redemption fee proceeds ............ 34,155 129,280
-------------- ------------
NET INCREASE FROM CAPITAL
SHARE TRANSACTIONS ............... 195,773,386 304,232,989
-------------- ------------
TOTAL INCREASE IN NET ASSETS ...... 350,068,765 446,117,583

NET ASSETS
Beginning of period ................ 809,948,375 363,830,792
-------------- ------------
End of period ...................... $1,160,017,140 $809,948,375
============== ============

CHANGE IN CAPITAL SHARES
Shares outstanding,
beginning of period ............... 50,097,938 29,505,941
-------------- ------------
Shares sold ........................ 14,649,646 27,379,055
Shares issued on
reinvestment of distributions ..... 1,689,461 --
Shares repurchased ................. (4,696,008) (6,787,058)
-------------- ------------
Net increase in capital shares .... 11,643,099 20,591,997
-------------- ------------
Shares outstanding, end of period 61,741,037 50,097,938
============== ============

------
(1) Unaudited.

The accompanying notes are an integral part of these financial statements.

Financial Highlights
PRIMECAP Odyssey Stock Fund
----------------------------------------------------------------
FOR A CAPITAL SHARE OUTSTANDING THROUGHOUT THE PERIOD

THE FOLLOWING INFORMATION SHOULD BE READ IN CONJUNCTION WITH THE FINANCIAL
STATEMENTS AND NOTES THERETO APPEARING ELSEWHERE IN THIS SEMIANNUAL REPORT.

Net asset value, beginning of period $13.48 $11.69 $10.10 $15.22 $13.48 $11.48
INCOME FROM INVESTMENT OPERATIONS:
Net investment income .............. 0.11 0.095 0.10 0.06 0.07 0.03
Net realized and unrealized
gain (loss) on investments ........ 2.00 1.79 1.55 (4.99) 1.79 1.97
------ ------ ------ ------ ------ ------
Total from investment operations ..... 2.11 1.88 1.65 (4.93) 1.86 2.00
------ ------ ------ ------ ------ ------
LESS DISTRIBUTIONS:
Dividends from net investment income (0.11) (0.09) (0.06) (0.07) (0.04) (0.00)(4)
Distributions from realized gain ... -- -- -- (0.12) (0.08) (0.00)(4)
------ ------ ------ ------ ------ ------
Total distributions .................. (0.11) (0.09) (0.06) (0.19) (0.12) (0.00)
------ ------ ------ ------ ------ ------
Redemption fee proceeds .............. 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4)
------ ------ ------ ------ ------ ------
Net asset value, end of period ....... $15.48 $13.48 $11.69 $10.10 $15.22 $13.48
====== ====== ====== ====== ====== ======

Total return ......................... 15.72%(3) 16.14% 16.55% (32.73%) 13.88% 17.48%

RATIOS/SUPPLEMENTAL DATA:
Net assets, end of period .......... $797.2 $607.1 $179.7 $187.0 $ 216.4 $ 88.4
(millions)

RATIO OF EXPENSES TO AVERAGE
NET ASSETS ......................... 0.65%(2) 0.71% 0.80% 0.79% 0.81% 0.99%

RATIO OF NET INVESTMENT INCOME
TO AVERAGE NET ASSETS .............. 1.44%(2) 1.37%(5) 0.96% 0.51% 0.59% 0.41%

Portfolio turnover rate .............. 21.59%(3) 3.35% 33.55% 9.66% 5.87% 4.09%

------
(1) Unaudited.
(2) Annualized.
(3) Not Annualized.
(4) Amount represents less than $0.01 per share.
(5) Investment income per share reflects a special dividend of $0.05. Excluding
the special dividend, the ratio of net investment income to average net
assets would have been 0.74%.

The accompanying notes are an integral part of these financial statements.

FINANCIAL HIGHLIGHTS
PRIMECAP ODYSSEY GROWTH FUND
----------------------------------------------------------------
FOR A CAPITAL SHARE OUTSTANDING THROUGHOUT THE PERIOD

THE FOLLOWING INFORMATION SHOULD BE READ IN CONJUNCTION WITH THE FINANCIAL
STATEMENTS AND NOTES THERETO APPEARING ELSEWHERE IN THIS SEMIANNUAL REPORT.

Net asset value,
beginning of period ................ $ 14.70 $ 12.18 $10.07 $15.71 $13.76 $11.62
-------- -------- ------ ------ ------ ------
Income from investment operations:
Net investment income .............. 0.03 0.02 0.03 0.03 0.04 0.01
Net realized and unrealized
gain (loss) on investments ........ 2.52 2.53 2.11 (5.59) 2.07 2.14
-------- -------- ------ ------ ------ ------
Total from investment operations ..... 2.55 2.55 2.14 (5.56) 2.11 2.15
-------- -------- ------ ------ ------ ------
LESS DISTRIBUTIONS:
Dividends from net investment income (0.01) (0.03) (0.03) (0.04) (0.02) (0.00)(4)
Distributions from realized gain ... -- -- -- (0.04) (0.14) (0.01)
-------- -------- ------ ------ ------ ------
Total distributions ................. (0.01) (0.03) (0.03) (0.08) (0.16) (0.01)
-------- -------- ------ ------ ------ ------
Redemption fee proceeds ............. 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4)
-------- -------- ------ ------ ------ ------

Net asset value, end of period ....... $ 17.24 $ 14.70 $12.18 $10.07 $15.71 $13.76
======== ======== ====== ====== ====== ======

Total return ......................... 17.39%(3) 20.96% 21.39% (35.55%) 15.46% 18.49%

RATIOS/SUPPLEMENTAL DATA:
Net assets, end of period ............ $1,978.9 $1,451.2 $706.5 $412.4 $512.0 $202.2
(millions)

Ratio of expenses to average net ..... 0.66%(2) 0.68% 0.71% 0.71% 0.75% 0.89%
assets

Ratio of net investment income
to average net assets ................ 0.44%(2) 0.15% 0.35% 0.26% 0.30% 0.19%

Portfolio turnover rate .............. 6.10%(3) 4.93% 12.49% 12.72% 4.83% 6.87%

------
(1) Unaudited.
(2) Annualized.
(3) Not Annualized.
(4) Amount represents less than $0.01 per share.

The accompanying notes are an integral part of these financial statements.

FINANCIAL HIGHLIGHTS
PRIMECAP ODYSSEY AGGRESSIVE GROWTH FUND
----------------------------------------------------------------
FOR A CAPITAL SHARE OUTSTANDING THROUGHOUT THE PERIOD

THE FOLLOWING INFORMATION SHOULD BE READ IN CONJUNCTION WITH THE FINANCIAL
STATEMENTS AND NOTES THERETO APPEARING ELSEWHERE IN THIS SEMIANNUAL REPORT.

SIX MONTHS YEAR YEAR YEAR YEAR YEAR
ENDED ENDED ENDED ENDED ENDED ENDED
APR. 30, OCT. 31, OCT. 31, OCT. 31, OCT. 31, OCT. 31,
2011(1) 2010 2009 2008 2007 2006
--------- -------- -------- -------- -------- --------
Net asset value, beginning of period $ 16.17 $12.33 $ 9.46 $16.03 $13.92 $11.24
-------- ------ ------ ------ ------ ------
Income from investment operations:
Net investment loss .............. (0.01) (0.05) (0.05) (0.06) (0.03) (0.02)
Net realized and unrealized
gain (loss) on investments ...... 3.16 3.89 2.92 (6.42) 2.34 2.70
-------- ------ ------ ------ ------ ------
Total from investment operations ... 3.15 3.84 2.87 (6.48) 2.31 2.68
-------- ------ ------ ------ ------ ------
LESS DISTRIBUTIONS:
Distributions from realized gain ... (0.53) -- -- (0.09) (0.20) --
-------- ------ ------ ------ ------ ------
Redemption fee proceeds ............ 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4) 0.00(4)
-------- ------ ------ ------ ------ ------

Net asset value, end of period ..... $ 18.79 $16.17 $12.33 $ 9.46 $16.03 $13.92
======== ====== ====== ====== ====== ======

Total return ....................... 20.00%(3) 31.14% 30.34% (40.60%) 16.76% 23.84%

RATIOS/SUPPLEMENTAL DATA:
Net assets, end of period .......... $1,160.0 $809.9 $363.8 $225.4 $375.2 $119.9
(millions)

Ratio of expenses to average net ... 0.68%(2) 0.71% 0.77% 0.78% 0.78% 0.99%
assets

Ratio of net investment loss
to average net assets ............ (0.13%)(2) (0.45%) (0.54%) (0.46%) (0.25%) (0.33%)

Portfolio turnover rate ............ 6.00%(3) 15.34% 19.70% 24.32% 6.02% 12.30%

(1) Unaudited.
(2) Annualized.
(3) Not Annualized.
(4) Amount represents less than $0.01 per share.

The accompanying notes are an integral part of these financial statements.

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
----------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED)

(1) ORGANIZATION

PRIMECAP Odyssey Funds (the "Trust") was organized on June 8, 2004 as a Delaware
statutory trust and is registered as an open-end management investment company
under the Investment Company Act of 1940, as amended (the "1940 Act"). The Trust
is comprised of three series: PRIMECAP Odyssey Stock Fund, PRIMECAP Odyssey
Growth Fund, and PRIMECAP Odyssey Aggressive Growth Fund (the "Funds"), each of
which is diversified within the meaning of the 1940 Act. PRIMECAP Management
Company (the "Investment Advisor") serves as investment advisor to the Funds.
Each Fund commenced operations on November 1, 2004.

Each Fund's investment objective is to provide long-term capital appreciation.
Each Fund is authorized to issue unlimited shares of beneficial interest. All
shares within each Fund have equal rights with respect to voting.

(2) SIGNIFICANT ACCOUNTING POLICIES

The Funds consistently follow the accounting policies set forth below which are
in conformity with accounting principles generally accepted in the United States
of America.

A. SECURITY VALUATION.
Securities traded on a national securities exchange are valued at the
last reported sales price at the close of regular trading on each day
the exchanges are open for trading. Securities listed on the NASDAQ
Global Market, the NASDAQ Global Select Market, and the NASDAQ Capital
Market are valued using the NASDAQ Official Closing Price, which may
not necessarily represent the last sale price. Quotations of foreign
securities in a foreign currency are valued daily in U.S. dollars on
the basis of the foreign currency exchange rates prevailing at the
time such valuation is determined. Foreign currency exchange rates
generally are determined prior to the close of the New York Stock
Exchange (the "NYSE"). Securities traded on an exchange for which
there have been no sales are valued at the mean between the bid and
asked price. Securities for which quotations are not readily available
are stated at their respective fair values as determined in good faith
by a valuation committee of the Investment Advisor in accordance with
procedures approved by the Trust's board of trustees. In determining
fair value, the Funds take into account all relevant factors and
available information. Consequently, the price of a security used by a
Fund to calculate its net asset value per share ("NAV") may differ
from quoted or published prices for the same security. Fair value
pricing involves subjective judgments, and there is no single standard
for determining a security's fair value. As a result, different mutual
funds could reasonably arrive at a different fair value for the same
security. It is possible that the fair value determined for a security
is materially different from the value that could be realized upon the
sale of that security or from the values that other mutual funds may
determine.

Investments in other funds are valued at their respective net asset
values as determined by those funds, in accordance with the 1940 Act.

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

Foreign securities are recorded in the financial statements after
their prices are converted to U.S. dollars based on the applicable
exchange rate at the end of the period. The Funds do not isolate that
portion of the results of operations arising as a result of changes in
the currency exchange rate from the fluctuations arising as a result
of changes in the market prices of investments during the period.

B. SHARE VALUATION.
The net asset value per share ("NAV") of a Fund is calculated by
dividing the sum of the value of the securities held by the Fund, plus
cash or other assets, minus all liabilities (including estimated
accrued expenses), by the total number of shares outstanding of the
Fund. The result is rounded to the nearest cent. The Funds' shares
will not be priced on the days on which the NYSE is closed for
trading.

C. FOREIGN CURRENCY.
Values of investments denominated in foreign currencies are converted
into U.S. dollars using the spot market rate of exchange at the time
of valuation. Purchases and sales of investments and dividend and
interest income are converted into U.S. dollars using the spot market
rate of exchange prevailing on the respective dates of such
translations. The gain or loss resulting from changes in foreign
exchange rates is included with net realized and unrealized gain or
loss from investments, as appropriate. Foreign securities and currency
transactions may involve certain considerations and risks not
typically associated with those of domestic origin.

D. FEDERAL INCOME TAXES.
Each Fund has elected to be treated as a "regulated investment
company" under Subchapter M of the Internal Revenue Code (the "IRC").
The Funds intend to distribute substan- tially all of their taxable
income and any capital gains in excess of applicable capital loss
carryforwards. Accordingly, no provision for Federal income taxes has
been made in the accompanying financial statements.

The Funds may be subject to foreign taxes on income, gains on
investments, or currency repatriation, a portion of which may be
recoverable. The Funds will accrue such taxes and recoveries as
applicable based upon their current interpretations of the tax rules
and regulations that exist in the markets in which they invest.

Each Fund has adopted accounting standards regarding recognition and
measurement of tax positions taken on a tax return. No material
uncertain tax positions existed in any Fund as of April 30, 2011. As
of April 30, 2011, open tax years include the tax years ended October
31, 2007 through 2010. The Funds are also not aware of any tax
positions for which it is reasonably possible that the total amounts
of unrecognized tax benefits will significantly change in the next six
months. The Funds recognize interest and penalties, if any, related
to unrecognized tax benefits as income tax expense in the Statement of
Operations. During the period, the Funds did not incur any interest or
penalties.

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

E. ALLOCATION OF EXPENSES.
Each Fund is charged for those expenses directly attributable to it.
Expenses that are not directly attributable to a Fund are allocated
among the Funds by an appropriate method based on the nature of the
expense.

F. SECURITY TRANSACTIONS, INVESTMENT INCOME, AND DISTRIBUTIONS.
Security transactions are accounted for on the trade date. Dividend
income and distributions to shareholders are recorded on the
ex-dividend date, and interest income is recognized on the accrual
basis. Realized gains and losses are evaluated on the basis of
identified costs. Premiums and discounts on the purchase of securities
are amortized/ accreted using the effective interest method.
Accounting principles generally accepted in the United States of
America require that permanent financial reporting and tax differences
be reclassified in the capital accounts.

G. USE OF ESTIMATES.
The preparation of financial statements in conformity with accounting
principles generally accepted in the United States of America requires
management to make estimates and assumptions that affect the reported
amounts of assets and liabilities and disclosure of contingent assets
and liabilities at the date of the financial statements, and the
reported amounts of revenues and expenses during the reporting period.
Actual results could differ from these estimates.

H. INDEMNIFICATION OBLIGATIONS.
Under the Trust's organizational documents, its current and former
officers and trustees are indemnified against certain liabilities
arising out of the performance of their duties to the Funds. In
addition, in the normal course of business, the Funds enter into
contracts that contain a variety of representations and warranties
that provide general indemnifications. The Funds' maximum exposure
under these arrangements is unknown as this would involve future
claims that may be made against the Funds that have not yet occurred.
Based on experience, the Funds would expect the risk of loss to be
remote.

(3) INVESTMENT TRANSACTIONS

The cost of purchases and the proceeds from sales of securities, excluding
short-term investments, for the six months ended April 30, 2011 were as follows:

FUND PURCHASES SALES
---- ------------ ------------
PRIMECAP Odyssey Stock Fund ............... $273,364,665 $151,875,851
PRIMECAP Odyssey Growth Fund .............. $333,401,133 $ 97,992,279
PRIMECAP Odyssey Aggressive Growth Fund ... $216,927,173 $ 54,691,138

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

(4) FAIR VALUE OF THE FINANCIAL INSTRUMENTS

The Funds have adopted fair valuation accounting standards which establish an
authoritative definition of fair value and set forth a hierarchy for measuring
fair value. These standards require additional disclosure about the various
inputs and valuation techniques used to develop the measurements of fair value
and a discussion of changes in valuation techniques and related inputs during
the period. These standards define fair value as the price that would be
received to sell an asset or paid to transfer a liability in an orderly
transaction between market participants on the measurement date. The fair value
hierarchy is organized into three levels based upon the assumptions (referred to
as "inputs") used to value the asset or liability. These standards state that
"observable inputs" reflect the assumptions that market participants would use
in valuing an asset or liability based on market data obtained from independent
sources. "Unobservable inputs" reflect the entity's own assumptions about the
inputs market participants would use to value the asset or liability.

Various inputs are used in determining the value of each Fund's investments.
These inputs are summarized in the three broad levels below:

Level 1 - Unadjusted quoted prices in active markets for identical
securities to which the trust has access at the date of
measurement.

Level 2 - Other significant observable inputs (including quoted prices for
similar or related securities in both active and inactive
markets, interest rates, foreign exchange rates, and fair value
estimates for foreign securities indices).

Level 3 - Significant unobservable inputs to the extent observable inputs
are unavailable (including the Funds' own assumptions in
determining fair value of investments based on the best available
information).

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

The following table provides the fair value measurements of applicable Fund
assets by level within the fair value hierarchy for each Fund as of April 30,
2011. There were no significant transfers into or out of Level 1 and Level 2
during the reporting period. These assets are measured on a recurring basis.

QUOTED PRICES
IN ACTIVE SIGNIFICANT
MARKETS FOR OTHER SIGNIFICANT
IDENTICAL OBSERVABLE UNOBSERVABLE
ASSETS INPUTS INPUTS
FUND DESCRIPTION (LEVEL 1) (LEVEL 2) (LEVEL 3) TOTAL
------------- ------------- -------------- ----------- ------------- -------
PRIMECAP Equity
ODYSSEY STOCK Common Stock $ 781,019,811 $ -- $ -- $ 781,019,811
FUND -------------- ----- ----- --------------
Total Equity $ 781,019,811 $ -- $ -- $ 781,019,811
-------------- ----- ----- --------------
Short-Term $ 14,606,275 $ -- $ -- $ 14,606,275
-------------- ----- ----- --------------
Investments
Total Investments
in Securities $ 795,626,086 $ -- $ -- $ 795,626,086
============== ===== ===== ==============
PRIMECAP Equity
ODYSSEY GROWTH Common Stock $1,894,590,791 $ -- $ -- $1,894,590,791
FUND -------------- ----- ----- --------------
Total Equity $1,894,590,791 $ -- $ -- $1,894,590,791
-------------- ----- ----- --------------
Short-Term $ 83,064,411 $ -- $ -- $ 83,064,411
-------------- ----- ----- --------------
Investments
Total Investments
in Securities $1,977,655,202 $ -- $ -- $1,977,655,202
============== ===== ===== ==============

PRIMECAP Equity
ODYSSEY Common Stock $1,108,362,413 $ -- $ -- $1,108,362,413
AGGRESSIVE -------------- ----- ----- --------------
GROWTH FUND Total Equity $1,108,362,413 $ -- $ -- $1,108,362,413
-------------- ----- ----- --------------
Short-Term $ 54,159,249 $ -- $ -- $ 54,159,249
-------------- ----- ----- --------------
Investments
Total Investments
in Securities $1,162,521,662 $ -- $ -- $1,162,521,662
============== ===== ===== ===============

------
Refer to each Fund's respective Schedule of Investments for the breakdown of
major categories.

(5) DISTRIBUTION TO SHAREHOLDERS

Net investment income and net realized gains differ for financial statement and
tax purposes due to differing treatments of deferred wash sale losses.

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

As of October 31, 2010, the components of capital on a tax basis were as
follows:
PRIMECAP
PRIMECAP PRIMECAP Odyssey
ODYSSEY ODYSSEY AGGRESSIVE
STOCK FUND GROWTH FUND GROWTH FUND
------------- -------------- ------------
Cost of investments
for tax purposes(1) ......... $ 562,380,581 $1,297,133,832 $722,523,447
============= ============== ============
Gross tax unrealized
appreciation ................ 79,683,082 260,985,245 164,880,361
Gross tax unrealized
depreciation ................ (29,846,067) (107,360,252) (76,515,282)
------------- -------------- ------------
Net tax unrealized appreciation $ 49,837,015 $ 153,624,993 $ 88,365,079
============= ============== ============
Undistributed ordinary income $ 4,150,713 $ 1,066,130 $ --
Undistributed long-term
capital gain ................ -- -- 27,849,253
------------- -------------- ------------
Total distributable earnings $ 4,150,713 $ 1,066,130 $ 27,849,253
------------- -------------- ------------
Other accumulated loss......... $ (29,278,962) $ (10,428,534) $ --
------------- -------------- ------------
Total accumulated gain ........ $ 24,708,766 $ 144,262,589 $116,214,332
============= ============== ============

------
(1) At October 31, 2010, the basis of investments for federal income tax
purposes differs from the cost for financial reporting purposes due to the tax
deferral of losses on wash sales.

At October 31, 2010, the PRIMECAP Odyssey Stock Fund and PRIMECAP Odyssey Growth
Fund had capital loss carryovers of $29,278,962 an$10,428,534, respectively, of
which $3,593,931 and $689,857 expire on October 31, 2016, and $25,685,031 and
$9,738,677 expire on October 31, 2017, respectively.

Tax components of dividends paid during the six months ended April 30, 2011 and
the year ended October 31, 2010 were as follows:

APRIL 30, 2011
-----------------------------
ORDINARY LONG-TERM
INCOME CAPITAL GAIN
DISTRIBUTIONS DISTRIBUTIONS
------------- -------------
PRIMECAP Odyssey Stock Fund ................ $5,099,941 $ --
PRIMECAP Odyssey Growth Fund ............... $1,416,348 $ --
PRIMECAP Odyssey Aggressive Growth Fund .... $ -- $27,881,437

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

October 31, 2010
------------------------------
Ordinary Long-Term
Income Capital Gain
Distributions Distributions
------------- -------------
PRIMECAP Odyssey Stock Fund ............... $1,831,079 $ --
PRIMECAP Odyssey Growth Fund .............. $1,825,837 $ --
PRIMECAP Odyssey Aggressive Growth Fund ... $ -- $ --

The Funds designated as long-term capital gain dividends, pursuant to Internal
Revenue Code Section 852(b)(3), the amounts necessary to reduce the earnings and
profits of the Funds related to net capital gains to zero for the tax year ended
October 31, 2010.

In December 2010, the Regulated Investment Company Modernization Act (the "RIC
Act") was enacted by Congress and signed into law. Under the RIC Act, new
capital losses may be carried forward indefinitely and retain the character of
the original loss. The RIC Act, among other things, also contains provisions
aimed at preventing disqualification under the IRC for inadvertent failures to
comply with the asset diversification and qualifying income tests, exempts RICs
from the preferential dividend rule, and repeals the 60-day designation
requirement for certain pay-through income and gains. Most of the provisions of
the RIC Act will apply to the Funds beginning in the 2013 fiscal year.
Management is evaluating the implications of the RIC Act, if any, and the impact
on the Funds' financial statements is being assessed.

(6) INVESTMENT ADVISORY AND OTHER AGREEMENTS

The Trust has entered into an investment management agreement with the
Investment Advisor on behalf of each Fund. Under the terms of the agreement,
each of the Funds will pay a fee equal to the following annual percentages of
average net assets:

FOR THE FIRST ASSETS IN EXCESS OF
$100,000,000 $100,000,000
PER FUND PER FUND
------------- -------------------
PRIMECAP Odyssey Stock Fund ................... 0.60% 0.55%
PRIMECAP Odyssey Growth Fund .................. 0.60% 0.55%
PRIMECAP Odyssey Aggressive Growth Fund ....... 0.60% 0.55%

The Bank of New York Mellon Corporation serves as the Funds' custodian. U.S.
Bancorp Fund Services, LLC ("USBFS") serves as the administrator, fund
accountant, and transfer agent to the Funds. Quasar Distributors, LLC, an
affiliate of USBFS, serves as the Funds' distributor.

NOTES TO FINANCIAL STATEMENTS
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
FOR THE SIX MONTHS ENDED APRIL 30, 2011 (UNAUDITED) - CONTINUED

(7) OTHER AFFILIATES

Certain of the Funds' investments are in companies that are considered to be
affiliated companies of a Fund because the Fund owns more than 5% of the
outstanding voting securities of the company. Transactions during the period in
securities of these companies were as follows:

PRIMECAP Odyssey Growth Fund
CURRENT PERIOD TRANSACTIONS
--------------------------------------------------
MARKET PROCEEDS MARKET
VALUE AS OF FROM REALIZED VALUE AT
OCTOBER 31, PURCHASES SECURITIES DIVIDEND GAIN APRIL 30,
COMMON STOCK 2010 AT COST SOLD INCOME (LOSS) 2011
------------ ----------- --------- ---------- -------- ------- ---------
Conceptus, Inc. 31,457,075 591,600 -- -- -- 34,775,023
ImmunoGen, Inc. 46,196,400 -- -- -- -- 75,083,200
----------- ---------- ---------- -------- ----- ------------
Total $77,653,475 $ 591,600 -- -- -- $109,858,223
=========== ========== ========== ======== ===== ============

PRIMECAP Odyssey Aggressive Growth Fund

CURRENT PERIOD TRANSACTIONS
--------------------------------------------------
MARKET PROCEEDS MARKET
VALUE AS OF FROM REALIZED VALUE AT
OCTOBER 31, PURCHASES SECURITIES DIVIDEND GAIN APRIL 30,
COMMON STOCK 2010 AT COST SOLD INCOME (LOSS) 2011
------------ ----------- --------- ---------- -------- ------- ---------
Conceptus, Inc. 21,382,497 2,269,604 -- -- -- 25,764,242
Dyax, Corp 11,223,647 2,036,300 -- -- -- 11,250,000
Smart Balance, Inc. 11,433,670 729,968 -- -- -- 16,316,076
----------- ---------- ---------- -------- ----- ------------
Total $44,039,814 $5,035,872 -- -- -- $ 53,330,318
=========== ========== ========== ======== ===== ============

(8) SUBSEQUENT EVENTS

The funds have evaluated subsequent events through the issuance of the financial
statements and determined that no events have occurred that require disclosure.

ADDITIONAL INFORMATION
PRIMECAP ODYSSEY FUNDS
-------------------------------------------------------------
(UNAUDITED)

PROXY VOTING PROCEDURES

The Investment Advisor votes proxies relating to portfolio securities in
accordance with procedures that have been approved by the Trust's board of
trustees. You may obtain a description of these procedures, free of charge, by
calling toll-free 1-800-729-2307. This information is also available through the
Securities and Exchange Commission's ("SEC") website at http://www.sec.gov.

PROXY VOTING RECORD

Information regarding how the Funds voted proxies relating to the portfolio
securities during the most recent 12-month period ended June 30 is available
without charge, upon request, by calling toll-free 1-800-729-2307. This
information is also available through the SEC's website at http://www.sec.gov.

FORM N-Q DISCLOSURE

The Trust files its complete schedules of each Fund's portfolio holdings with
the SEC for the first and third quarters of each fiscal year on Form N-Q. The
Trust's Forms N-Q are available on the SEC's website at http://www.sec.gov. The
Trust's Forms N-Q may be reviewed and copied at the Commission's Public
Reference Room in Washington, DC, and information on the operation of the Public
Reference Room may be obtained by calling 1-800-SEC-0330. This information is
also available, without charge, by calling toll-free 1-800-729-2307.

MANAGEMENT
PRIMECAP ODYSSEY FUNDS
-------------------------------------------------------------
(UNAUDITED)

PORTFOLIO MANAGERS

PRIMECAP Management Company has five portfolio managers who together have more
than 180 years of investment experience. Each of these five individuals manages
a portion of the PRIMECAP Odyssey Stock Fund and the PRIMECAP Odyssey Growth
Fund. The PRIMECAP Odyssey Aggressive Growth Fund is primarily managed by
Messrs. Schow, Kolokotrones, Fried, and Mordecai. A small portion of each Fund's
assets may be managed by individuals in the Investment Advisor's research
department. The portfolio managers primarily responsible for overseeing the
Funds' investments are:

NAME YEARS OF EXPERIENCE
--------------------------------------------------
Howard B. Schow 55
Mitchell J. Milias 47
Theo A. Kolokotrones 41
Joel P. Fried 26
Alfred W. Mordecai 14

OFFICERS AND TRUSTEES

The Trust's officers, who administer the Funds' daily operations, are appointed
by the board of trustees. The trustees are responsible for the overall
management of the Trust, including establishing the Funds' policies and general
supervision and review of their investment activities. The Statement of
Additional Information includes additional information about the Trust's
trustees and is available, without charge, by calling 1-800-729-2307 or at the
Funds' website at http://www.odysseyfunds.com.

Executive Officers. The table below sets forth certain information about each of
the Trust's executive officers.

Theo A. Kolokotrones Co-Chief Indefinite; Vice-Chairman, Director, Portfolio
225 South Lake Ave. Executive Since 09/04 Manager, and Principal
Pasadena, CA 91101-3005 Officer PRIMECAP Management Company
(1946)

MANAGEMENT
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
(UNAUDITED) - CONTINUED

POSITION(S) TERM OF OFFICE;
NAME, ADDRESS HELD LENGTH OF PRINCIPAL OCCUPATION(S)
(YEAR OF BIRTH) WITH TRUST TIME SERVED DURING PAST 5 YEARS
-----------------------------------------------------------------------------------------------
Joel P. Fried Co-Chief Indefinite; President, Director, Portfolio Manager,
225 South Lake Ave. Executive Since 09/04 and Principal
Pasadena, CA 91101-3005 Officer PRIMECAP Management Company
(1962) and
Trustee
-----------------------------------------------------------------------------------------------
Michael J. Ricks Chief Indefinite; Director of Fund Administration,
225 South Lake Ave. Financial Since 03/11 PRIMECAP Management Company
Pasadena, CA 91101-3005 Officer, (Since 2011); Vice President, Fund
(1977) Chief Administration and Compliance,
Administrative U.S. Bancorp Fund Services, LLC
Officer, and (2001-2011)
Secretary
-----------------------------------------------------------------------------------------------
Karen Chen Vice Indefinite; Chief Compliance Officer, Director of
225 South Lake Ave. President Since 10/04 Compliance and Reporting
Pasadena, CA 91101-3005 of PRIMECAP Management Company
(1973) Compliance
and Chief
Compliance
Officer
and AML
Officer
-----------------------------------------------------------------------------------------------

"INDEPENDENT" TRUSTEES. The table below sets forth certain each of the
information about trustees of the Trust who is not an "interested person" of the
Trust as defined in the 1940 Act ("Independent Trustees").

Benjamin F. Hammon Chairman Indefinite; Retired; Director, 3 None
225 South Lake Ave. of the Since 09/04 Institutional Equity
Pasadena, CA Board and Sales, Salomon Smith
91101-3005 Trustee Barney Inc. (1963-1998)
(1935)
-------------------------------------------------------------------------------------------------
Wayne H. Smith Chairman Indefinite; Retired; President, 3 None
225 South Lake Ave. of the Audit Since 09/04 Wayne H. Smith
Pasadena, CA Committee Consulting, Inc. (2002-
91101-3005 and Trustee 2007); Vice President,
(1941) Financial Services, Avery
Dennison Corporation
(2001-2002); Vice
President, Financial
Services, and Treasurer,
Avery Dennison
Corporation (1999-
2001)
-------------------------------------------------------------------------------------------------

MANAGEMENT
PRIMECAP ODYSSEY FUNDS
--------------------------------------------------------------------------------
(UNAUDITED) - CONTINUED

Joseph G. Uzelac Trustee Indefinite; Retired; Managing 3 None
225 South Lake Ave. Since 10/07 Director, Lehman
Pasadena, CA Brothers Global
91101-3005 Investment Bank
(1944) (1988-2007)
-------------------------------------------------------------------------------------------------
Elizabeth D. Obershaw Trustee Indefinite; Managing Director, 3 None
225 South Lake Ave. Since 06/08 Horsley Bridge
Pasadena, CA Partners, a California-
91101-3005 based investment advisor
(1960) (2007-present); Vice
President and
Chief Investment
Officer, Hewlett-Packard
Company (1991-2007);
Hewlett-Packard
Company (1983-1991)
-------------------------------------------------------------------------------------------------

(1) Fund Complex includes any funds, series of funds, or trusts that share the
same advisor or that hold themselves out to investors as related companies.

"INTERESTED" TRUSTEES. The table below sets forth certain information about each
of the trustees of the Trust who is an "interested person" of the Trust as
defined by the 1940 Act.

NUMBER OF
TERM OF PORTFOLIOS OTHER
POSITION(S) OFFICE; IN FUND DIRECTORSHIPS
NAME, ADDRESS HELD LENGTH OF PRINCIPAL OCCUPATION(S) COMPLEX BY HELD BY
(YEAR OF BIRTH) WITH TRUST TIME SERVED DURING PAST 5 YEARS TRUSTEE(1) TRUSTEE
-------------------------------------------------------------------------------------------------
Joel P. Fried (2) Co-Chief Indefinite; President, Director, 3 None
225 South Lake Ave. Executive Since 09/04 Portfolio Manager,
Pasadena, CA Officer and and Principal
91101-3005 Trustee PRIMECAP
(1962) Management Company
-------------------------------------------------------------------------------------------------

(1) Fund Complex includes any funds, series of funds, or trusts that share the
same advisor or that hold themselves out to investors as related companies.

(2) Mr. Fried is an "interested person" of the Trust, as defined by the 1940
Act, because of his employment with PRIMECAP Management Company, the
investment advisor to the Trust.

Investment Advisor
PRIMECAP MANAGEMENT COMPANY
225 South Lake Avenue, Suite 400
Pasadena, California 91101

o
Distributor
QUASAR DISTRIBUTORS, LLC
615 East Michigan Street, 4th Floor
Milwaukee, Wisconsin 53202

o
Custodian
THE BANK OF NEW YORK MELLON CORPORATION
One Wall Street
New York, New York 10286

o
Transfer Agent
U.S. BANCORP FUND SERVICES, LLC
615 East Michigan Street, 3rd Floor
Milwaukee, Wisconsin 53202

o
Administrator
U.S. BANCORP FUND SERVICES, LLC
2020 East Financial Way, Suite 100
Glendora, California 91741

o
Legal Counsel
BINGHAM McCUTCHEN LLP 355 South
Grand Avenue, Suite 4400
Los Angeles, California 90071

o
Independent Registered Public Accounting
Firm PRICEWATERHOUSECOOPERS LLP
Three Embarcadero Center
San Francisco, California 94111

THIS REPORT IS INTENDED FOR THE SHAREHOLDERS OF THE PRIMECAP ODYSSEY FUNDS AND
MAY NOT BE USED AS SALES LITERATURE UNLESS PRECEDED OR ACCOMPANIED BY A CURRENT
PROSPECTUS.

PAST PERFORMANCE RESULTS SHOWN IN THIS REPORT SHOULD NOT BE CONSIDERED A
REPRESENTATION OF FUTURE PERFORMANCE. SHARE PRICE AND RETURNS WILL FLUCTUATE SO
THAT SHARES, WHEN REDEEMED, MAY BE WORTH MORE OR LESS THAN THEIR ORIGINAL COST.
STATEMENTS AND OTHER INFORMATION HEREIN ARE DATED AND ARE SUBJECT TO CHANGE.

PRIMECAP, PRIMECAP ODYSSEY, AND THE PRIMECAP ODYSSEY LOGO ARE TRADEMARKS OF
PRIMECAP MANAGEMENT COMPANY.

ITEM 2. CODE OF ETHICS.

Not applicable for semi-annual reports.

ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable for semi-annual reports.

ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable for semi-annual reports.

ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable to registrants who are not listed issuers (as defined in Rule
10A-3 under the Securities Exchange Act of 1934).

ITEM 6. INVESTMENTS.

Schedule of Investments is included as part of the report to shareholders filed
under Item 1 of this Form.

ITEM 7. DISCLOSURE OF PROXY VOTING POLICIES AND PROCEDURES FOR CLOSED-END
MANAGEMENT INVESTMENT COMPANIES.

Not applicable to open-end investment companies.

ITEM 8. PORTFOLIO MANAGERS OF CLOSED-END MANAGEMENT INVESTMENT COMPANIES.

Not applicable to open-end investment companies.

ITEM 9. PURCHASES OF EQUITY SECURITIES BY CLOSED-END MANAGEMENT INVESTMENT
COMPANY AND AFFILIATED PURCHASERS.

Not applicable to open-end investment companies.

ITEM 10. SUBMISSION OF MATTERS TO A VOTE OF SECURITY HOLDERS.

Not applicable.

ITEM 11. CONTROLS AND PROCEDURES.

(a) The Registrant's Co-Chief Executive Officers and Chief Financial Officer
have reviewed the Registrant's disclosure controls and procedures (as
defined in Rule 30a-3(c) under the Investment Company Act of 1940 (the
"Act")) as of a date within 90 days of the filing of this report, as
required by Rule 30a-3(b) under the Act and Rules 13a-15(b) or 15d-15(b)
under the Securities Exchange Act of 1934. Based on their review, such
officers have concluded that the disclosure controls and procedures are
effective in ensuring that information required to be disclosed in this
report is appropriately recorded, processed, summarized and reported and
made known to them by others within the Registrant and by the Registrant's
service provider.

(b) There were no changes in the Registrant's internal control over financial
reporting (as defined in Rule 30a-3(d) under the Act) that occurred during
the second fiscal quarter of the period covered by this report that has
materially affected, or is reasonably likely to materially affect, the
Registrant's internal control over financial reporting.

ITEM 12. EXHIBITS.

(1) Any code of ethics or amendment thereto, that is the subject of the
disclosure required by Item 2, to the extent that the registrant intends
to satisfy Item 2 requirements through filing an exhibit.
(a) Not applicable.

(2) A separate certification for each principal executive and principal
financial officer pursuant to Section 302 of the Sarbanes-Oxley Act of
2002. Filed herewith.

(3) Any written solicitation to purchase securities under Rule 23c-1 under
the Act sent or given during the period covered by the report by or on
behalf of the registrant to 10 or more persons. Not applicable to open-end
investment companies.

(b) Certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
Furnished herewith.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934 and
the Investment Company Act of 1940, the registrant has duly caused this report
to be signed on its behalf by the undersigned, thereunto duly authorized.

PRIMECAP Odyssey Funds

By /s/ JOEL P. FRIED
-----------------------------------------
Joel P. Fried, Co-Chief Executive Officer

Date June 22, 2011

By /S/ HOWARD B. SCHOW
-------------------------------------------
Howard B. Schow, Co-Chief Executive Officer

Date June 22, 2011

By /S/ THEO A. KOLOKOTRONES
------------------------------------------------
Theo A. Kolokotrones, Co-Chief Executive Officer

Date June 22, 2011

Pursuant to the requirements of the Securities Exchange Act of 1934 and
the Investment Company Act of 1940, this report has been signed below by the
following persons on behalf of the registrant and in the capacities and on the
dates indicated.

By /s/ JOEL P. FRIED
-----------------------------------------
Joel P. Fried, Co-Chief Executive Officer

Date June 22, 2011

By /S/ HOWARD B. SCHOW
-------------------------------------------
Howard B. Schow, Co-Chief Executive Officer

Date June 22, 2011

By /S/ THEO A. KOLOKOTRONES
------------------------------------------------
Theo A. Kolokotrones, Co-Chief Executive Officer

Date June 22, 2011

By /S/ MICHAEL J. RICKS
------------------------------------------------
Michael J. Ricks, Chief Financial Officer

Date June 22, 2011