[Janus Letterhead]



March 27, 2007

VIA EDGAR
---------

Mr. Larry Greene
Division of Investment Management
U.S. Securities and Exchange Commission
100 F Street, NE
Washington, D.C. 20549-0505

Re:      JANUS INVESTMENT FUND (the "Registrant")
         1933 Act File No. 2-34393
         1940 Act File No. 811-1879
         Post-Effective Amendment No. 119

Dear Mr. Greene:

This letter is to respond to your comments made by telephone on Wednesday,
February 14, 2007 with respect to Janus Investment Fund Post-Effective Amendment
No. 119. On behalf of the Registrant, responses to your comments are as follows:

COMBINED JANUS EQUITY FUNDS PROSPECTUS
--------------------------------------

1.       COMMENT: The Staff requested that the Registrant reflect in writing all
         comments and responses and carry over comments, as applicable, to other
         Janus Investment Fund prospectuses and Statements of Additional
         Information ("SAIs").

         RESPONSE: The Registrant acknowledges the comment.

2.       COMMENT: The Staff requested that the Registrant clarify disclosure to
         reflect which Funds were classified as diversified and which were
         classified as non-diversified.

         RESPONSE: As required by Item 2(c)(1)(iv) of Form N-1A, the Registrant
         includes prospectus disclosure and related risks for Funds that are
         classified as non-diversified. In addition, as required by Item 11 of
         Form N-1A, each Fund's classification, whether diversified or
         non-diversified, is included in the SAI.

3.       COMMENT: The Staff inquired as to the Registrant's compliance with the
         designation of an officer of the Funds to supervise anti-money
         laundering as required under the USA Patriot Act. The Staff also
         requested that Patriot Act disclosure be included in the Funds'
         Prospectuses.





         RESPONSE: The Trustees of the Registrant have designated an officer of
         the Funds to supervise the Registrant's anti-money laundering program,
         as required under the USA Patriot Act. The Trustees have also approved
         a vendor for purposes of implementing requirements for customer
         identification. In addition, as discussed, information regarding the
         USA Patriot Act, which is not required in the prospectus or SAI, is
         addressed in the Funds' account application materials, as well as new
         account supplemental materials.

4.       COMMENT: The Staff inquired whether the Registrant is in compliance,
         currently and in the past, with its Fidelity bond filing requirements.

         RESPONSE: To the best of its knowledge, the Registrant is currently in
         compliance with its Fidelity bond filing requirements.

5.       COMMENT: The Staff indicated that in the cases of funds with global,
         international, foreign, or worldwide in their names, that such funds
         should each invest in securities of at least ten countries and have
         invested at least 40% of its assets in securities of foreign countries,
         excluding the U.S.

         RESPONSE: Consistent with investment policies and restrictions of each
         of these funds, the Registrant has previously added or revised
         disclosure as appropriate to reflect that such funds invest in several
         countries. The Registrant believes its investment policies are
         consistent with formal SEC guidance.

6.       COMMENT: The Staff indicated that the percentage of any country
         concentration (within emerging markets) should be disclosed in the
         prospectus.

         RESPONSE: In response to prior Staff comment regarding emerging markets
         disclosure, the Registrant has included the specific percentage of
         emerging markets allocation as of a Fund's fiscal year end, as
         applicable. The Registrant believes that specific country allocation is
         more appropriate in shareholder reports and Form N-Q. Disclosure was
         previously added directing investors to shareholder reports and Form
         N-Q for a summary of investments by country.

7.       COMMENT: The Staff inquired whether the word "Enterprise" in Janus
         Enterprise Fund had a specific meaning and is described in the Fund's
         investment strategies.

         RESPONSE: The Registrant confirms that the word "Enterprise" is not
         intended to suggest that the Fund focuses its investments in a
         particular type of investment.

8.       COMMENT: The Staff commented that if the Funds' disclosure stating
         "Within the parameters of its specific investment policies, the Fund
         may invest without limit in foreign equity and debt securities" allows
         the Funds to invest in emerging markets, Registrant should add emerging
         markets to the strategy discussion.




         RESPONSE: As discussed during our call, although the Funds do not have
         a particular mandate to invest in emerging market securities, they are
         not precluded from doing so. If a particular Fund does invest 5% or
         more of its assets in emerging markets, the respective Fund's
         Risk/Return Summary is updated to include appropriate disclosure on
         emerging market risks.

9.       COMMENT: The Staff stated its view that Rule 13a-1 promulgated under
         the Investment Company Act of 1940 is intended to apply to
         non-diversified funds which temporarily become diversified, not
         non-diversified funds which normally operate as diversified funds.

         RESPONSE: Item 2 of Form N-1A indicates that a Fund classified as
         non-diversified include disclosure that it "may" invest a larger
         portion of its assets in fewer issuers. The Registrant believes its
         disclosure is consistent with Form N-1A.

10.      COMMENT: The Staff asked for clarification regarding the management of
         Janus Research Fund and whether the Fund has a policy for investing in
         certain sectors.

         RESPONSE: Disclosure reflects that James Goff is responsible for the
         day-to-day operations of the Fund, and the Registrant believes that
         such disclosure is consistent with Item 5 of Form N-1A. The Fund does
         not have a policy to invest in certain sectors.

11.      COMMENT: In regards to Janus Global Life Sciences Fund, the Staff
         commented that additional clarity be provided in relation to "companies
         with life sciences orientation" specifically as it relates to the
         Fund's concentration policy.

         RESPONSE: The Fund's Principal Investment Strategies section currently
         contains disclosure as to what the portfolio manager considers as
         investments that have a "life sciences" orientation. The disclosure is
         designed to provide additional information regarding the types of
         companies that could appear in the portfolio, rather than imply that
         there are specific "industries" in the sense of those which might be
         used to determine compliance with a concentration policy.

12.      COMMENT: The Staff inquired whether Janus Global Life Sciences Fund has
         a concentration policy, as disclosure provides that "[t]he Fund
         concentrates its investments in related industry groups."

         RESPONSE: The Registrant confirms that the Fund does not have a policy
         to concentrate its investments and has revised the disclosure to
         reflect that "[t]he Fund focuses its investments in related industry
         groups."

13.      COMMENT: The Staff sought confirmation that emerging markets risk
         disclosure exists for those Funds which "may invest without limit in
         foreign equity and debt securities."




         RESPONSE: The Registrant confirms that emerging markets risk factors
         are included for funds that, within the parameters of their specific
         investment policies, have a certain level of emerging markets exposure
         (generally 5% or more).

14.      COMMENT: The Staff inquired whether the word "Contrarian" in Janus
         Contrarian Fund had a specific meaning and is described in the Fund's
         investment strategies.

         RESPONSE: The Registrant confirms that the word "Contrarian" is not
         intended to suggest that the Fund focuses its investments in a
         particular type of investment. A "contrarian-type" strategy is,
         however, discussed under the Fund's Principal Investment Strategies and
         in "Frequently Asked Questions About Principal Investment Strategies."

15.      COMMENT: With respect to Janus Fundamental Equity Fund, what does
         disclosure concerning "other securities with equity characteristics"
         mean?

         RESPONSE: The disclosure, which lists equity securities in which the
         Fund may invest, also includes the concept that other securities may be
         identified which have equity characteristics.

16.      COMMENT: The Staff inquired whether the word "Opportunities" in Janus
         Global Opportunities Fund had a specific meaning and is described in
         the Fund's investment strategies.

         RESPONSE: The Registrant confirms that the word "Opportunities" is not
         intended to suggest that the Fund focuses its investments in a
         particular type of investment.

17.      COMMENT: The Staff indicated that the footnotes to the Fees and
         Expenses table should follow the expense examples.

         RESPONSE: The Registrant believes that the most effective presentation
         of the information is reflected in the current disclosure and is
         consistent with Item 3 of Form N-1A. Additionally, General Instruction
         C.1(a) to Form N-1A provides that a fund should use document design
         techniques that promote effective communication, which the Registrant
         believes is consistent with its current disclosure.

18.      COMMENT: The performance fee structure is more properly characterized
         as a fixed-rate that is adjusted rather than a "rate that adjusts
         upward or downward."

         RESPONSE: The disclosure, which was also contained in the proxies
         provided to shareholders, does in fact indicate that the fee is
         calculated by applying a fixed-rate advisory fee plus or minus a
         performance fee adjustment.

19.      COMMENT: The Staff inquired whether applicable fee waiver agreements
         have been included as exhibits to the filing.




         RESPONSE: The Registrant confirms that its practice, although not
         required under Part C to Form N-1A, is to include the investment
         advisory fee waiver agreements as exhibits in a subsequent
         post-effective amendment filing.

20.      COMMENT: The Staff inquired whether any of the Funds in the Prospectus
         were subject to expense recoupment as a result of any fees waived by
         Janus Capital.

         RESPONSE: The Registrant confirms that Janus Capital does not have the
         ability to recoup expenses as a result of any fees waived for any of
         the Funds included in the Prospectus.

21.      COMMENT: The Staff asked for an explanation of the waiting period for
         Janus Global Research Fund and Janus Research Fund.

         RESPONSE: The Registrant has developed specific policies in an attempt
         to ensure equitable dissemination of analyst ideas. As discussed, a
         waiting period may not be applicable in all circumstances. For example,
         the investment idea may have already been disseminated among investment
         staff.

22.      COMMENT: The language regarding maintaining liquidity contained in the
         Cash Position section should be revised.

         RESPONSE: The Registrant believes the disclosure describing a Fund's
         ability to temporarily increase its cash position, under unusual
         circumstances, to protect assets or maintain liquidity in certain
         circumstances (e.g., to meet unusually large redemptions) is
         appropriate and no further revision is needed.

23.      COMMENT: The Staff inquired whether risk disclosure is included for
         securities described under "Other Types of Investments."

         RESPONSE: The Registrant confirms that disclosure is included in the
         Prospectus and/or SAI, as appropriate.

24.      COMMENT: The Staff inquired whether the required new "Fund of Funds"
         rule disclosure has been included in the Prospectus.

         RESPONSE: To the extent that the Funds have underlying fund fees and
         expenses that reach the required disclosure threshold, such disclosure
         is included in the Fees and Expenses table.

25.      COMMENT: The Staff requested that the Registrant add disclosure that in
         cases of short sale transactions, the risk of loss may be unlimited.

         RESPONSE: The Registrant believes that appropriate disclosure is
         reflected in the SAI under the description of "Short Sales."




26.      COMMENT: The Staff commented that it is necessary to discuss the risks
         of unsponsored depository receipts under "Foreign Securities."

         RESPONSE: The risks of unsponsored American Depository Receipts are
         discussed in the SAI under "Depositary Receipts."

27.      COMMENT: Regarding the Funds' securities lending program, the Staff
         inquired: (i) whether the Funds maintain voting rights; (ii) how
         collateral is handled; and (iii) any amounts paid by the Funds for the
         securities lending program.

         RESPONSE: The Funds generally do not have the right to vote proxies
         while they are lent, but the Funds may attempt to call back the
         security and vote the proxy. All loans are continuously secured by
         collateral which may consist of cash, U.S. Government securities,
         domestic and foreign short-term debt instruments, letters of credit,
         money market mutual funds or other money market accounts, or such other
         collateral as permitted by the SEC. Amounts paid are not required under
         Form N-1A or other formal SEC guidance.

28.      COMMENT: The disclosure does not reflect that financials are audited.

         RESPONSE: Information regarding the audited financials is routinely
         added following the 485(a) filing.

JANUS SMART PORTFOLIOS COMBINED PROSPECTUS
------------------------------------------

29.      COMMENT: The Staff inquired what is meant by "Normal Asset Allocation
         Range" with respect to the Janus Smart Portfolios.

         RESPONSE: At any point in time, the specific asset allocation may vary
         from their long term target due to factors such as asset fluctuations
         and specific investments. The table provides detail of the range of
         variance of the specific allocations.

30.      COMMENT: The Staff inquired whether the Janus Smart Portfolios may
         invest in Class I Shares of Janus Adviser INTECH Risk-Managed Value
         Fund.

         RESPONSE: The Registrant confirms that the Janus Smart Portfolios may
         invest in Class I Shares of Janus Adviser INTECH Risk-Managed Value
         Fund.

31.      COMMENT: The Staff asked for clarification regarding disclosure which
         provides that "the portfolios intend to allocate assets among stocks
         and bonds . . . ."

         RESPONSE: The Registrant has revised disclosure to reflect that "the
         portfolios intend to allocate assets among underlying funds that invest
         in stocks and bonds . . . ."




32.      COMMENT: The Staff indicated that there appears to be a conflict
         between disclosure in the SAI that the Portfolios have no industry
         concentration but that the Prospectus reflects that indirect
         concentration may occur.

         RESPONSE: While the Portfolios do not have a 1940 Act concentration
         policy, its investments among underlying funds may result in 'indirect'
         concentration. Such disclosure is intended as a risk factor and not
         specific industry concentration.

33.      COMMENT: With respect to emerging markets risk and the Janus Smart
         Portfolios' investments in underlying funds, the Staff inquired whether
         any of the companies which the Portfolios own through investments in
         underlying funds have any dealings or contacts with countries
         identified by the U.S. State Department as state sponsors of terrorism
         or countries subject to sanctions administered by the U.S. Treasury
         Department's Office of Financial Assets Control, such as Sudan, North
         Korea, Iran, Syria and Cuba. If so, please advise the Staff of the
         Registrant's view as to their materiality to the Portfolios and whether
         they pose a material investment risk to persons considering purchasing
         shares of the Portfolios. The Staff indicated that, in preparing a
         response, consider that evaluations of materiality should not be based
         solely on quantitative factors but should include considerations of all
         factors, including the potential impact of corporate activities upon a
         company's reputation and share value that a reasonable investor would
         deem important in making an investment decision.

         RESPONSE: The Registrant confirms that no trading operations have been
         established in any of the countries listed. The Registrant also
         confirms that there are no investments in the countries identified by
         the U.S. State Department as state sponsors of terrorism or countries
         subject to sanctions administered by the U.S. Treasury Department's
         Office of Financial Assets Control.

34.      COMMENT: The Staff inquired whether Wilshire Associates Inc. serves as
         an adviser or as a consultant.

         RESPONSE: Wilshire Associates Inc. is considered a consultant which
         provides research and advice regarding asset allocation methodologies.
         Wilshire also provides qualitative and quantitative evaluations that
         the portfolio manager may use in implementing allocations for the
         underlying funds.

35.      COMMENT: The Staff commented that certain disclosure appears to be in
         all capital letters and that the SEC discourages the use of all capital
         letters to emphasize disclosure.

         RESPONSE: As discussed, the disclosure referenced appears in bold face
         type, not all capital letters. The EDGAR process converts bold face
         type into all capital letters.






JANUS SMART PORTFOLIOS COMBINED SAI
-----------------------------------

36.      COMMENT: The Staff stated that to the extent that the Portfolios engage
         in borrowing, risk disclosure should be included in the Prospectus.

         RESPONSE: The Registrant acknowledges the comment, and confirms that
         leverage risk would be included in the Prospectus as appropriate.

37.      COMMENT: The Staff inquired whether the Janus Smart Portfolios may
         invest in Class I Shares of Janus Adviser INTECH Risk-Managed Value
         Fund.

         RESPONSE: The Registrant confirms that the Janus Smart Portfolios may
         invest in Class I Shares of Janus Adviser INTECH Risk-Managed Value
         Fund.

38.      COMMENT: The Staff requested that the Registrant add disclosure that in
         cases of short sale transactions, the risk of loss may be unlimited.

         RESPONSE: The Registrant confirms that disclosure reflecting the
         comment exists in the SAI under the description of "Short Sales."

39.      COMMENT: The Staff stated that per Section 18, the Portfolios may only
         borrow from banks.

         RESPONSE: The Registrant acknowledges the comment.

40.      COMMENT: The Staff inquired whether any expense recoupment has occurred
         related to the Portfolios.

         RESPONSE: The Registrant confirms that no amounts have been recouped.

41.      COMMENT: The Staff stated that any benchmark related to portfolio
         manager compensation should be disclosed.

         RESPONSE: The disclosure provides that the subjective benchmarks
         include operating margin, asset flows in Janus funds, product line and
         distribution expansion, brand reinforcement, and specific employee
         goals. The overall assessment of the factors is based on management's
         judgment.

JANUS BOND AND MONEY MARKET FUNDS PROSPECTUS
--------------------------------------------

42.      COMMENT: With respect to Janus High-Yield Fund, the Staff inquired as
         to what types of investments are "other high-yielding securities."

         RESPONSE: "Other high-yielding securities" may consist of investments
         that have the characteristics of below investment grade securities.





43.      COMMENT: The Staff stated that Janus High-Yield Fund disclosure
         relating to market swings in one or more countries could have more of
         an effect on Fund performance than a more geographically diversified
         portfolio and should also discuss associated risks.

         RESPONSE: The "Frequently Asked Questions About Certain Risks" section
         of the Prospectus contains additional disclosure relating to the
         potential risks associated with the Fund's investments, if any, in
         foreign securities.

44.      COMMENT: With respect to Janus Short-Term Bond Fund, the Staff asked
         how the policy of investing in intermediate-term fixed-income
         securities is consistent with the Fund's name.

         RESPONSE: The adopting release for Rule 35d-1 (the Fund Names Rule)
         notes that the Division of Investment Management has required funds
         with "short-term" in their names to maintain a dollar-weighted average
         maturity of no more than three years. Although this Fund may invest to
         some extent in intermediate-term fixed income securities, consistent
         with the Division's policy, the Fund's policy disclosed in the
         Prospectus is to maintain an average weighted effective maturity of
         three years or less under normal circumstances.

45.      COMMENT: The Staff asked whether disclosure which provides that Janus
         Federal Tax-Exempt Fund can invest up to 20% of its net assets in
         taxable securities, and may invest without limit in cash and cash
         equivalents that may be federally taxable is consistent with the Fund's
         strategy to invest 80% of its net assets in short-term municipal
         securities whose interest is exempt from federal income taxes.

         RESPONSE: The Registrant confirms that the disclosure is consistent
         with the Fund's strategy. The Fund's investment in cash or cash
         equivalents is only to the extent that the portfolio manager cannot
         locate investment opportunities with desirable risk/reward
         characteristics.

46.      COMMENT: The Staff stated that per Section 18, the Portfolios may only
         borrow from banks.

         RESPONSE: The Registrant acknowledges the comment.

47.      COMMENT: The Staff inquired whether any of the Funds in the Janus Bond
         and Money Market Funds Prospectus were subject to expense recoupment as
         a result of any fees waived by Janus Capital.

         RESPONSE: The Registrant confirms that Janus Capital does not have the
         ability to recoup expenses as a result of any fees waived for the Funds
         in the Janus Bond and Money Market Funds Prospectus.





48.      COMMENT: The disclosure does not reflect that the financial highlights
         are audited.

         RESPONSE: Information regarding the audited financial highlights is
         routinely added following the 485(a) filing.

49.      COMMENT: The Staff requested that the Registrant provide a Tandy
         representation in a response letter to be filed as correspondence
         separate from the filing.

         RESPONSE: The Registrant provides its response below.

The Registrant acknowledges responsibility for the adequacy and accuracy of the
disclosure in the filings. In addition, the Registrant acknowledges that Staff
comments, or changes to disclosure in response to Staff comments in the filings
reviewed by the Staff, do not foreclose the Commission from taking any action
with respect to the filing.

If you have any concerns regarding the above responses, please call me at (303)
394-6459. Thank you for your assistance in this matter.

Sincerely,

/s/ Stephanie Grauerholz-Lofton

Stephanie Grauerholz-Lofton
Vice President

cc:      Larry Greene, Esq.
         Kelley Abbott Howes, Esq.
         Donna Brungardt
         Cindy Antonson