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 811-01311
                                                     --------------------
                            THE GABELLI MATHERS FUND
        -----------------------------------------------------------------
               (Exact name of registrant as specified in charter)

                              ONE CORPORATE CENTER,
                            RYE, NEW YORK 10580-1422
        -----------------------------------------------------------------
               (Address of principal executive offices) (Zip code)

                                 BRUCE N. ALPERT
                               GABELLI FUNDS, LLC
                              ONE CORPORATE CENTER,
                            RYE, NEW YORK 10580-1422
        -----------------------------------------------------------------
                     (Name and address of agent for service)

       registrant's telephone number, including area code: 1-800-422-3554
                                                           --------------
                   Date of fiscal year end: DECEMBER 31, 2003
                                            -----------------
                     Date of reporting period: JUNE 30, 2003
                                               -------------


Form N-CSR is to be used by management investment companies to file reports with
the Commission not later than 10 days after the  transmission to stockholders of
any report that is required to be transmitted to  stockholders  under Rule 30e-1
under the Investment Company Act of 1940 (17 CFR 270.30e-1).  The Commission may
use the information provided on Form N-CSR in its regulatory, disclosure review,
inspection, and policymaking roles.

A registrant  is required to disclose the  information  specified by Form N-CSR,
and the  Commission  will make this  information  public.  A  registrant  is not
required to respond to the  collection  of  information  contained in Form N-CSR
unless the Form  displays a  currently  valid  Office of  Management  and Budget
("OMB")  control number.  Please direct comments  concerning the accuracy of the
information  collection  burden  estimate and any  suggestions  for reducing the
burden to Secretary,  Securities and Exchange Commission,  450 Fifth Street, NW,
Washington,  DC 20549-0609.  The OMB has reviewed this collection of information
under the clearance requirements of 44 U.S.C. ss. 3507.






ITEM 1. REPORTS TO STOCKHOLDERS.

                            THE GABELLI MATHERS FUND

                               SEMI-ANNUAL REPORT
                                  JUNE 30, 2003


TO OUR SHAREHOLDERS,

      We are  changing  the way we provide  portfolio  managers'  commentary  to
shareholders  of our Funds.  Our  shareholder  reports have typically  contained
commentary  on  each  portfolio  manager's   assessment  of  the  stock  market,
individual  stocks and how economic  events affect their  thinking in managing a
specific Fund. We have always provided  details about  performance and presented
returns,  both good and bad,  hopefully  in a clear and concise  fashion.  These
comments have been included as part of each Fund's quarterly,  semi-annual,  and
annual financial statements.

      The Sarbanes-Oxley Act's new corporate governance  regulations now require
a Fund's  principal  executive  and  financial  officers  to certify  the entire
contents of  shareholder  reports in a filing with the  Securities  and Exchange
Commission on form N-CSR.  This  certification  covers the  portfolio  manager's
commentary  and  subjective  opinions  if they are  attached to or a part of the
financial statements.

      Rather than ask our portfolio  managers to eliminate their opinions and/or
restrict  their  commentary  to  historical  facts only,  we are removing  their
commentary from the financial statements and sending it to you separately.  As a
result,  this commentary will no longer be considered part of a Fund's financial
report and therefore will not be subject to the officers' certifications.

      We  trust  that  you  understand   that  our  approach  is  an  unintended
consequence of the  ever-increasing  regulatory  requirements  affecting  public
companies generally.  We hope the specific  certification  requirements of these
new  regulations  will be  modified  as  they  relate  to  mutual  funds,  since
investment  companies have different  corporate  structures and objectives  than
other public companies.

                                             Sincerely yours,




                                             /S/ BRUCE N. ALPERT
                                             Bruce N. Alpert
                                             Chief Operating Officer
August 8, 2003                               Gabelli Funds, LLC

THE GABELLI MATHERS FUND
PORTFOLIO OF INVESTMENTS -- JUNE 30, 2003 (UNAUDITED)
- --------------------------------------------------------------------------------

                                                   MARKET
      SHARES                           COST         VALUE
      ------                           ----        ------
              COMMON STOCKS -- 0.5%
              AEROSPACE -- 0.3%
       6,000  Veridian Corp.+ .....$   208,310  $   209,340
                                   -----------  -----------
              BUSINESS SERVICES -- 0.0%
         500  Quintiles
                Transnational Corp.+     7,120        7,095
                                   -----------  -----------
              FINANCIAL SERVICES -- 0.0%
       2,000  Factual Data Corp.+ .     34,860       34,760
                                   -----------  -----------
              FINANCIAL SERVICES: BANKS -- 0.0%
         500  Port Financial Corp.      26,900       26,940
                                   -----------  -----------
              FOOD AND BEVERAGE -- 0.1%
         500  Dreyer's Grand Ice Cream
                Holdings Inc.,
                Cl. A .............     39,595       39,260
                                   -----------  -----------
              REAL ESTATE -- 0.1%
       1,000  Chateau Communities
                Inc. ..............     29,940       29,590
       1,000  Insignia Financial
                Group Inc.+ .......     11,140       11,110
                                   -----------  -----------
                                        41,080       40,700
                                   -----------  -----------
              TOTAL COMMON STOCKS .    357,865      358,095
                                   -----------  -----------

   PRINCIPAL
    AMOUNT
   ---------
              U.S. GOVERNMENT OBLIGATIONS -- 91.4%
 $70,000,000  U.S. Treasury Bill,
                1.020%++,
                07/03/03 (c) ...... 69,996,034   69,996,034
                                   -----------  -----------
              REPURCHASE AGREEMENTS -- 8.4%
   1,414,501  State Street Bank & Trust Co.,
                1.080%, dated 06/30/03,
                due 07/01/03, proceeds
                at maturity,
                $1,414,544 (a) ....  1,414,501    1,414,501
   5,000,000  Warburg Dillon Reed,
                1.090%, dated 06/30/03,
                due 07/01/03, proceeds
                at maturity,
                $5,000,151 (b) ....  5,000,000    5,000,000
                                   -----------  -----------
              TOTAL REPURCHASE
                AGREEMENTS ........  6,414,501    6,414,501
                                   -----------  -----------
              TOTAL INVESTMENTS --
                100.3% ............$76,768,400   76,768,630
                                   ===========
              OTHER ASSETS AND
                LIABILITIES (NET) -- (0.3)% ...    (240,379)
                                                -----------
              NET ASSETS -- 100.0% ............ $76,528,251
                                                ===========

                                                   MARKET
      SHARES  COMMON STOCKS          PROCEEDS       VALUE
      ------  -------------          --------      ------
              SECURITIES SOLD SHORT
       1,000  Carnival Corp. ......$   (25,859) $   (32,510)
       3,000  Diamonds Trust ......   (255,343)    (269,730)
       5,000  Ford Motor Co. ......    (57,225)     (54,950)
       1,000  Gap Inc. (The) ......    (16,949)     (18,760)
       5,000  Harley-Davidson Inc.    (207,760)    (199,300)
       2,000  Home Depot Inc. .....    (57,782)     (66,240)
       1,000  La-Z-Boy Inc. .......    (21,459)     (22,380)
       1,000  McDonald's Corp. ....    (17,099)     (22,060)
       1,000  NIKE, Inc., Cl. B ...    (53,092)     (53,490)
       2,000  Polaris
                Industries Inc. ...   (112,595)    (122,800)
       1,000  Research in
                Motion Ltd.+ ......    (18,969)     (21,610)
       2,000  Sherwin-Williams Co.     (55,217)     (53,760)
      13,000  Standard & Poor's
                Depository Receipts (1,297,979)  (1,269,190)
       4,000  Starbucks Corp.+ ....    (96,751)     (98,080)
      30,000  Tiffany & Co. .......   (710,224)    (980,400)
       4,000  Toro Co. ............   (128,296)    (159,000)
                                   -----------  -----------
              TOTAL SECURITIES
                SOLD SHORT ........$(3,132,600) $(3,444,260)
                                   ===========  ===========


- ----------------
              For Federal tax purposes:
              Aggregate cost ...................$76,768,400
                                                ===========
              Gross unrealized appreciation ....$     1,070
              Gross unrealized depreciation ....       (840)
                                                -----------
              Net unrealized appreciation/
                 (depreciation) ................$       230
                                                ===========
- ----------------
 (a)  Collateralized by U.S. Treasury Bond, 7.625%, due 02/15/25, market value
      $1,424,375.
 (b)  Collateralized by U.S. Treasury Bond, 1.75%, due 12/31/04, market value
      $5,044,531.
 (c)  At June 30, 2003, $18,000,000 of the principal amount was pledged as
      collateral for short sale securities.
   +  Non-income producing security.
   ++ Represents annualized yield at date of purchase.

                 See accompanying notes to financial statements.

                                       2

                            THE GABELLI MATHERS FUND

STATEMENT OF ASSETS AND LIABILITIES
JUNE 30, 2003 (UNAUDITED)
- --------------------------------------------------------------------------------

ASSETS:
  Investments, at value (cost $70,353,899) ..     $  70,354,129
  Repurchase Agreements, at value
    (cost $6,414,501) .......................         6,414,501
  Cash ......................................            41,733
  Deposit at Brokers ........................           298,809
  Dividends and interest receivable .........               744
  Receivable for investments sold ...........         3,132,600
  Other assets ..............................             3,501
                                                  -------------
  TOTAL ASSETS ..............................        80,246,017
                                                  -------------
LIABILITIES:
  Securities sold short (proceeds $3,132,600)         3,444,260
  Payable for investments purchased .........           108,475
  Dividends payable on securities sold short              7,153
  Payable for investment advisory fees ......            63,052
  Payable for distribution fees .............            15,763
  Other accrued expenses and liabilities ....            79,063
                                                  -------------
  TOTAL LIABILITIES .........................         3,717,766
                                                  -------------
  NET ASSETS applicable to 7,132,837
    shares outstanding ......................     $  76,528,251
                                                  =============
NET ASSETS CONSIST OF:
  Shares of beneficial interest, at par value     $   7,132,837
  Additional paid-in capital ................       117,251,011
  Accumulated net investment income .........          (174,689)
  Accumulated net realized gain/(loss)
    on investments ..........................       (47,369,478)
  Net unrealized appreciation/(depreciation)
    on securities sold short ................          (311,660)
  Net unrealized appreciation/(depreciation)
    on investments ..........................               230
                                                  -------------
  NET ASSETS ................................     $  76,528,251
                                                  =============
  NET ASSET VALUE, offering and redemptions price
    per share (76,528,251 (DIVIDE) 7,132,837
    shares outstanding;100,000,000 shares
    authorized of $1.00 par value)                       $10.73
                                                         ======


STATEMENT OF OPERATIONS
FOR THE SIX MONTHS ENDED JUNE 30, 2003 (UNAUDITED)
- --------------------------------------------------------------------------------

INVESTMENT INCOME:
  Dividends ................................................... $     808
  Interest ....................................................   440,000
  Other Income ................................................     8,038
                                                                ---------
  TOTAL INVESTMENT INCOME .....................................   448,846
                                                                ---------
EXPENSES:
  Investment advisory fees ....................................   388,342
  Distribution fees ...........................................    97,086
  Trustees' fees ..............................................    27,019
  Shareholder services fees ...................................    18,897
  Custodian fees ..............................................    18,308
  Shareholder communications expenses .........................    16,030
  Legal and audit fees ........................................    13,862
  Registration fees ...........................................    11,032
  Dividends on securities sold short ..........................    11,248
  Miscellaneous expenses ......................................    21,711
                                                                ---------
  TOTAL EXPENSES ..............................................   623,535
                                                                ---------
  NET INVESTMENT LOSS .........................................  (174,689)
                                                                ---------
NET REALIZED AND UNREALIZED GAIN/(LOSS) ON
  INVESTMENTS AND SECURITIES SOLD SHORT:
  Net realized gain/(loss) on investments .....................  (134,330)
  Net realized gain/(loss) on securities sold short ...........   111,582
  Net change in unrealized appreciation/
    (depreciation) on investments and securities sold short ...  (420,111)
                                                                ---------
  NET REALIZED AND UNREALIZED GAIN/(LOSS) ON
    INVESTMENTS AND SECURITIES SOLD SHORT .....................  (442,859)
                                                                ---------
  NET INCREASE/(DECREASE) IN NET ASSETS
    RESULTING FROM OPERATIONS ................................. $(617,548)
                                                                =========

STATEMENT OF CHANGES IN NET ASSETS
- --------------------------------------------------------------------------------


                                                                    SIX MONTHS ENDED
                                                                      JUNE 30, 2003       YEAR ENDED
                                                                       (UNAUDITED)    DECEMBER 31, 2002
                                                                    ----------------  -----------------
                                                                                  
OPERATIONS:
  Net investment income/(loss) ..................................     $   (174,689)     $     (1,706)
  Net realized gain/(loss) on investments .......................         (134,330)      (12,725,118)
  Net realized gain/(loss) on securities sold short .............          111,582           285,919
  Net change in unrealized appreciation/(depreciation) on
    investments and securities sold short .......................         (420,111)        1,274,536
                                                                      ------------      ------------
  NET INCREASE/(DECREASE) IN NET ASSETS RESULTING FROM OPERATIONS         (617,548)      (11,166,369)
                                                                      ------------      ------------
DISTRIBUTIONS TO SHAREHOLDERS:
  Net investment income .........................................               --                --
                                                                      ------------      ------------
  TOTAL DISTRIBUTIONS TO SHAREHOLDERS ...........................               --                --
                                                                      ------------      ------------
SHARE TRANSACTIONS:
  Net increase/(decrease) in net assets from shares
     of beneficial interest transactions ........................       (3,681,380)       (5,899,570)
                                                                      ------------      ------------
  NET DECREASE IN NET ASSETS ....................................       (4,298,928)      (17,065,939)
                                                                      ------------      ------------
NET ASSETS:
  Beginning of period ...........................................       80,827,179        97,893,118
                                                                      ------------      ------------
  End of period .................................................     $ 76,528,251      $ 80,827,179
                                                                      ============      ============


                 See accompanying notes to financial statements.

                                        3

THE GABELLI MATHERS FUND
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
- --------------------------------------------------------------------------------

1. ORGANIZATION. The Gabelli Mathers Fund (the "Fund") was organized on June 17,
1999 as a Delaware business trust. The Fund commenced  investment  operations on
October 1, 1999 as the successor to the Mathers Fund,  Inc. (the "Mathers Fund")
which was  organized  on March 31, 1965 as a Maryland  corporation.  The Mathers
Fund  commenced  investment  operations  on  August  19,  1965.  The  Fund  is a
diversified,   open-end  management  investment  company  registered  under  the
Investment  Company Act of 1940, as amended (the "1940 Act"). The Fund's primary
objective is long-term capital appreciation.

2. SIGNIFICANT  ACCOUNTING POLICIES.  The preparation of financial statements in
accordance with accounting  principles  generally  accepted in the United States
requires  management to make estimates and assumptions  that affect the reported
amounts and disclosures in the financial statements. Actual results could differ
from those  estimates.  The  following  is a summary of  significant  accounting
policies followed by the Fund in the preparation of its financial statements.

SECURITY  VALUATION.  Portfolio  securities  listed or  traded  on a  nationally
recognized securities exchange or traded in the U.S. over-the-counter market for
which market quotations are readily available are valued at the last quoted sale
price or a market's  official  closing  price as of the close of business on the
day the  securities  are being  valued.  If there  were no sales  that day,  the
security is valued at the  average of the  closing  bid and asked  prices or, if
there were no asked  prices  quoted on that day,  then the security is valued at
the closing bid price on that day. If no bid or asked  prices are quoted on such
day,  the  security is valued at the most  recently  available  price or, if the
Board of Trustees so  determines,  by such other method as the Board of Trustees
shall  determine  in good faith,  to reflect its fair  market  value.  Portfolio
securities  traded on more than one national  securities  exchange or market are
valued according to the broadest and most  representative  market, as determined
by Gabelli Funds, LLC (the "Adviser").  Portfolio securities primarily traded on
foreign  markets are generally  valued at the preceding  closing  values of such
securities on their respective exchanges. Securities and assets for which market
quotations  are not  readily  available  are  valued  at  their  fair  value  as
determined in good faith under  procedures  established by and under the general
supervision of the Board of Trustees.  Short term debt securities with remaining
maturities of 60 days or less are valued at amortized cost,  unless the Board of
Trustees  determines  such does not reflect the securities  fair value, in which
case these  securities  will be valued at their fair value as  determined by the
Board of Trustees.  Debt instruments  having a maturity greater than 60 days for
which market  quotations are readily  available are valued at the latest average
of the bid and asked  prices.  If there were no asked prices quoted on such day,
the  security is valued  using the closing bid price.  Options are valued at the
last sale price on the  exchange on which they are  listed.  If no sales of such
options have taken place that day, they will be valued at the mean between their
closing bid and asked prices.

REPURCHASE  AGREEMENTS.  The Fund may  enter  into  repurchase  agreements  with
primary  government  securities dealers recognized by the Federal Reserve Board,
with member banks of the Federal Reserve System or with other brokers or dealers
that meet credit guidelines established by the Adviser and reviewed by the Board
of Trustees.  Under the terms of a typical repurchase agreement,  the Fund takes
possession  of an  underlying  debt  obligation  subject to an obligation of the
seller to repurchase,  and the Fund to resell,  the obligation at an agreed-upon
price and time, thereby  determining the yield during the Fund's holding period.
The Fund will always receive and maintain  securities as collateral whose market
value, including accrued interest,  will be at least equal to 102% of the dollar
amount  invested by the Fund in each  agreement.  The Fund

                                       4

THE GABELLI MATHERS FUND
NOTES TO FINANCIAL STATEMENTS (CONTINUED) (UNAUDITED)
- --------------------------------------------------------------------------------

will make  payment  for such  securities  only upon  physical  delivery  or upon
evidence  of  book  entry  transfer  of the  collateral  to the  account  of the
custodian.  To the extent that any repurchase  transaction  exceeds one business
day,  the  value  of the  collateral  is  marked-to-market  on a daily  basis to
maintain the adequacy of the collateral. If the seller defaults and the value of
the collateral declines or if bankruptcy  proceedings are commenced with respect
to the seller of the security,  realization of the collateral by the Fund may be
delayed or limited.

FUTURES  CONTRACTS.  The Fund may engage in futures contracts for the purpose of
hedging  against  changes in the value of its  portfolio  securities  and in the
value of  securities  it  intends  to  purchase.  Upon  entering  into a futures
contract,  the Fund is required to deposit  with the broker an amount of cash or
cash equivalents equal to a certain  percentage of the contract amount.  This is
known as the "initial margin." Subsequent payments ("variation margin") are made
or  received by the Fund each day,  depending  on the daily  fluctuation  of the
value of the  contract.  The daily  changes  in the  contract  are  included  in
unrealized gains or losses. The Fund recognizes a realized gain or loss when the
contract is closed. At June 30, 2003, there were no open futures contracts.

There are several  risks in  connection  with the use of futures  contracts as a
hedging device. The change in value of futures contracts  primarily  corresponds
with the value of their underlying instruments, which may not correlate with the
change in value of the hedged investments.  In addition,  there is the risk that
the Fund may not be able to  enter  into a  closing  transaction  because  of an
illiquid secondary market.

SECURITIES  SOLD SHORT. A short sale involves  selling a security which the Fund
does not own. The proceeds  received for short sales are recorded as liabilities
and the Fund records an unrealized  gain or loss to the extent of the difference
between the proceeds  received  and the value of the open short  position on the
day of  determination.  The Fund records a realized  gain or loss when the short
position is closed out. By entering into a short sale, the Fund bears the market
risk of an unfavorable change in price of the security sold short.  Dividends on
short sales are recorded as an expense by the Fund on the  ex-dividend  date and
interest expense is recorded on the accrual basis. Securities sold short at June
30, 2003 are reflected in the Portfolio of Investments.

SECURITIES  TRANSACTIONS  AND INVESTMENT  INCOME.  Securities  transactions  are
accounted  for on the  trade  date  with  realized  gain or loss on  investments
determined  by using the  identified  cost method.  Interest  income  (including
amortization  of premium  and  accretion  of  discount)  is  recorded as earned.
Dividend income is recorded on the ex-dividend date.

DIVIDENDS AND  DISTRIBUTIONS  TO  SHAREHOLDERS.  Dividends and  distributions to
shareholders  are recorded on the ex-dividend  date.  Income  distributions  and
capital  gain  distributions  are  determined  in  accordance  with  income  tax
regulations which may differ from generally  accepted  accounting  principles in
the United States.  These differences are primarily due to differing  treatments
of income and gains on various  investment  securities held by the Fund,  timing
differences and differing characterization of distributions made by the Fund.

PROVISION  FOR  INCOME  TAXES.  The Fund  intends  to  continue  to qualify as a
regulated  investment company under Subchapter M of the Internal Revenue Code of
1986, as amended. As a result, a Federal income tax provision is not required.

                                       5

THE GABELLI MATHERS FUND
NOTES TO FINANCIAL STATEMENTS (CONTINUED) (UNAUDITED)
- --------------------------------------------------------------------------------

The Fund has a net capital loss  carryforward for Federal income tax purposes at
December 31, 2002 of $47,346,730. This capital loss carryforward is available to
reduce future distributions of net capital gains to shareholders.  $4,819,701 of
the loss  carryforward  is  available  through  2003;  $22,226,886  is available
through 2004; $7,869,968 is available through 2006; and $12,430,175 is available
through 2010.

3.  INVESTMENT  ADVISORY  AGREEMENT.  The Fund has  entered  into an  investment
advisory  agreement (the "Advisory  Agreement")  with the Adviser which provides
that the Fund will pay the Adviser a fee,  computed  daily and paid monthly,  at
the  annual  rate of 1.00% of the value of the Fund's  average  net  assets.  In
accordance  with the  Advisory  Agreement,  the  Adviser  provides a  continuous
investment program for the Fund's portfolio,  oversees the administration of all
aspects of the Fund's  business  and  affairs and pays the  compensation  of all
Officers and Trustees of the Fund who are its affiliates.

4. DISTRIBUTION PLAN. On October 1, 1999, the Fund's Board of Trustees adopted a
distribution  plan (the  "Plan")  pursuant to Rule 12b-1 under the 1940 Act. For
the six months ended June 30, 2003, the Fund incurred distribution costs payable
to Gabelli & Company, Inc., an affiliate of the Adviser, of $97,086, or 0.25% of
average daily net assets,  the annual  limitation  under the Plan. Such payments
are accrued daily and paid monthly.

5. PORTFOLIO SECURITIES. Purchases and proceeds from the sales of securities for
the six months ended June 30, 2003, other than short term securities, aggregated
$8,773,466 and $8,734,147, respectively.

6. TRANSACTIONS WITH AFFILIATES.  During the six months ended June 30, 2003, the
Fund paid brokerage commissions of $5,805 to Gabelli & Company, Inc.

The cost of  calculating  the Fund's net asset value per share is a Fund expense
pursuant to the Advisory Agreement between the Fund and the Adviser. For the six
months ended June 30, 2003,  the Gabelli  Mathers  Fund  reimbursed  the Adviser
$17,400 in connection with the cost of computing the Fund's net asset value.

7. SHARES OF BENEFICIAL INTEREST.  Transactions in shares of beneficial interest
were as follows:


                                                            SIX MONTHS ENDED                     YEAR ENDED
                                                              JUNE 30, 2003                   DECEMBER 31, 2002
                                                       --------------------------      ----------------------------
                                                        SHARES          AMOUNT            SHARES          AMOUNT
                                                       --------       -----------      ----------      ------------
                                                                                           
Shares sold ..........................................  215,617       $ 2,323,317         729,693      $  8,237,339
Shares issued upon reinvestment of dividends .........       --                --              --                --
Shares redeemed ...................................... (557,226)       (6,004,697)     (1,246,765)      (14,136,909)
                                                       --------       -----------      ----------      ------------
    Net decrease ..................................... (341,609)      $(3,681,380)       (517,072)     $ (5,899,570)
                                                       ========       ===========      ==========      ============

                                       6

THE GABELLI MATHERS FUND
NOTES TO FINANCIAL STATEMENTS (CONTINUED) (UNAUDITED)
- --------------------------------------------------------------------------------

8.  FINANCIAL  HIGHLIGHTS.  Selected  data  for a share of  beneficial  interest
outstanding throughout each period:



                                          SIX MONTHS ENDED                     YEAR ENDED DECEMBER 31,
                                            JUNE 30, 2003   -----------------------------------------------------------
                                             (UNAUDITED)      2002         2001         2000         1999(A)     1998
                                          ----------------  --------     --------      -------      -------     ------
                                                                                      
OPERATING PERFORMANCE:
   Net asset value, beginning of period ....  $ 10.81       $ 12.25      $ 12.05      $ 11.94      $ 11.73      $ 13.06
                                              -------       -------      -------      -------      -------      -------
   Net investment income/(loss) ............    (0.02)        (0.00)*       0.30         0.49         0.46         0.58
   Net realized and unrealized
     gain/(loss) on investments ............    (0.06)        (1.44)        0.21         0.11         0.21        (1.26)
                                              -------       -------      -------      -------      -------      -------
   Total from investment operations ........    (0.08)        (1.44)        0.51         0.60         0.67        (0.68)
                                              -------       -------      -------      -------      -------      -------
DISTRIBUTIONS TO SHAREHOLDERS:
   Net investment income ...................       --            --        (0.31)       (0.49)       (0.46)       (0.65)
                                              -------       -------      -------      -------      -------      -------
   Total distributions .....................       --            --        (0.31)       (0.49)       (0.46)       (0.65)
                                              -------       -------      -------      -------      -------      -------
   NET ASSET VALUE, END OF PERIOD ..........  $ 10.73       $ 10.81      $ 12.25      $ 12.05      $ 11.94      $ 11.73
                                              =======       =======      =======      =======      =======      =======
   Total return+ ...........................  (0.74)%      (11.76)%        4.25%        5.02%        5.73%      (5.21)%
                                              =======       =======      =======      =======      =======      =======
RATIOS TO AVERAGE NET ASSETS
   AND SUPPLEMENTAL DATA:
   Net assets, end of period (in 000's) ....  $76,528       $80,827      $97,893      $99,855     $104,693     $108,548
   Ratio of net investment income/(loss)
     to average net assets .................  (0.45)%(c)    (0.00)%        2.45%        3.79%        3.50%        4.56%
   Ratio of operating expenses
     to average net assets .................    1.61%(b)(c)   1.63%(b)     1.35%(b)     1.34%(b)     1.24%(b)     1.16%(b)
   Portfolio turnover rate .................     254%          776%        1013%         977%         922%          67%

- --------------------------------
+   Total return represents aggregate total return of a hypothetical $1,000
    investment at the beginning of the period and sold at the end of the period
    including reinvestment of dividends. Total return for the period of less
    than one year is not annualized.
(a) Gabelli Funds, LLC became the sole investment adviser of the Fund on October
    1, 1999.
(b) The Fund incurred dividend expense on securities sold short for the six
    months ended June 30, 2003 and the years ended December 31, 2002, 2001,
    2000, 1999 and 1998. If the dividend expense had not been incurred, the
    ratios of operating expenses to average net assets would have been 1.58%,
    1.63%, 1.33%, 1.31%, 1.24%, and 1.12%, respectively.
(c) Annualized.
*   Amount is less than $0.005 per share.

                 See accompanying notes to financial statements.

                                        7

                            THE GABELLI MATHERS FUND
                              One Corporate Center
                            Rye, New York 10580-1422
                                   800-GABELLI
                                  800-422-3554
                                FAX: 914-921-5118
                            WEBSITE: WWW.GABELLI.COM
                            E-MAIL: INFO@GABELLI.COM
                   Net Asset Value available daily by calling
                           800-GABELLI after 6:00 P.M.
                                BOARD OF TRUSTEES

   Mario J. Gabelli, CFA                         Anthony R. Pustorino
   CHAIRMAN AND CHIEF                            CERTIFIED PUBLIC ACCOUNTANT
   INVESTMENT OFFICER                            PROFESSOR, PACE UNIVERSITY
   GABELLI ASSET MANAGEMENT INC.

   E. Val Cerutti                                Werner J. Roeder, MD
   CHIEF EXECUTIVE OFFICER                       VICE PRESIDENT/MEDICAL AFFAIRS
   CERUTTI CONSULTANTS, INC.                     LAWRENCE HOSPITAL CENTER

   Anthony J. Colavita                           Henry G. Van der Eb, CFA
   ATTORNEY-AT-LAW                               PRESIDENT AND CHIEF
   ANTHONY J. COLAVITA, P.C.                     EXECUTIVE OFFICER
                                                 THE GABELLI MATHERS FUND

   Vincent D. Enright                            Anthonie C. van Ekris
   FORMER SENIOR VICE PRESIDENT                  MANAGING DIRECTOR
   AND CHIEF FINANCIAL OFFICER                   BALMAC INTERNATIONAL, INC.
   KEYSPAN ENERGY CORP.

   Karl Otto Pohl
   FORMER PRESIDENT
   DEUTSCHE BUNDESBANK

                         OFFICERS AND PORTFOLIO MANAGER

   Henry G. Van der Eb, CFA                      Anne E. Morrissy, CFA
   PRESIDENT AND                                 EXECUTIVE VICE PRESIDENT
   PORTFOLIO MANAGER

   Bruce N. Alpert                               James E. McKee
   EXECUTIVE VICE PRESIDENT                      VICE PRESIDENT
   AND TREASURER                                 AND SECRETARY

   Heidi M. Stubner                              Edith L. Cook
   VICE PRESIDENT                                VICE PRESIDENT
                                   DISTRIBUTOR
                             Gabelli & Company, Inc.
                  CUSTODIAN, TRANSFER AGENT AND DIVIDEND AGENT
                       State Street Bank and Trust Company
                                  LEGAL COUNSEL
                    Skadden, Arps, Slate, Meagher & Flom LLP

- --------------------------------------------------------------------------------
This report is submitted for the general  information of the shareholders of The
Gabelli  Mathers Fund. It is not  authorized  for  distribution  to  prospective
investors unless preceded or accompanied by an effective prospectus.
- --------------------------------------------------------------------------------

GAB1726Q203SR


[GRAPHIC OMITTED]
PICTURE OF MARIO GABELLI

                         THE
                         GABELLI
                         MATHERS
                         FUND
                                                              SEMI-ANNUAL REPORT
                                                                   JUNE 30, 2003




ITEM 2. CODE OF ETHICS.

Not applicable.



ITEM 3. AUDIT COMMITTEE FINANCIAL EXPERT.

Not applicable.



ITEM 4. PRINCIPAL ACCOUNTANT FEES AND SERVICES.

Not applicable.



ITEM 5. AUDIT COMMITTEE OF LISTED REGISTRANTS.

Not applicable.



ITEM 6. [RESERVED]



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

Not applicable.



ITEM 8. [RESERVED]








ITEM 9. CONTROLS AND PROCEDURES.

(a)      The registrant's  principal executive and principal financial officers,
         or  persons  performing  similar  functions,  have  concluded  that the
         registrant's  disclosure  controls and  procedures  (as defined in Rule
         30a-3(c)  under the  Investment  Company Act of 1940,  as amended  (the
         "1940 Act") (17 CFR 270.30a-3(c)))  are effective,  as of a date within
         90 days of the filing date of the report that  includes the  disclosure
         required by this paragraph, based on their evaluation of these controls
         and  procedures  required by Rule  30a-3(b)  under the 1940 Act (17 CFR
         270.30a-3(b))  and Rules  13a-15(b) or 15d-15(b) under the Exchange Act
         (17 CFR 240.13a-15(b) or 240.15d-15(b)).




(b)      There  were  no  changes  in the  registrant's  internal  control  over
         financial reporting (as defined in Rule 30a-3(d) under the 1940 Act (17
         CFR  270.30a-3(d))  that occurred during the  registrant's  last fiscal
         half-year (the  registrant's  second fiscal half-year in the case of an
         annual report) that has materially affected, or is reasonably likely to
         materially  affect,  the  registrant's  internal control over financial
         reporting.




ITEM 10. EXHIBITS.

     (a)(1) Not applicable.

     (a)(2) Certifications  pursuant to Section 302 of the Sarbanes-Oxley Act of
            2002 are attached hereto.

     (b)    Certifications  pursuant to Section 906 of the Sarbanes-Oxley Act of
            2002 are attached hereto.









                                   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.

(registrant) THE GABELLI MATHERS FUND
            -------------------------------------------------------------

By (Signature and Title)*  /S/ BRUCE N. ALPERT
                           ----------------------------------------------
                           Bruce N. Alpert, Principal Executive Officer

Date                       09/03/03
     --------------------------------------------------------------------

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 (Signature and Title)*  /S/ BRUCE N. ALPERT
                           ----------------------------------------------
                           Bruce N. Alpert, Principal Executive Officer

Date                       09/03/03
     --------------------------------------------------------------------


By (Signature and Title)*  /S/ GUS A. COUTSOUROS
                           ----------------------------------------------
                           Gus A. Coutsouros, Principal Financial Officer

Date                       09/03/03
     --------------------------------------------------------------------


* Print the name and title of each signing officer under his or her signature.