EXHIBIT (i)


                          AMERICAN CENTURY INVESTMENTS
                                4500 MAIN STREET
                          KANSAS CITY, MISSOURI 64111

September 27, 2007

American Century Mutual Funds, Inc.
4500 Main Street
Kansas City, Missouri  64111

Ladies and Gentlemen:

     I have acted as counsel to American Century Mutual Funds,  Inc., a Maryland
corporation (the "Company"), in connection with Post-Effective Amendment No. 121
(the  "PEA") to the  Company's  Registration  Statement  on Form N-1A (File Nos.
2-14213, 811-0816),  relating to the public offering from time to time of any or
all of the  Company's  authorized  shares  of common  stock,  par value One Cent
($0.01) per share,  that have been  classified  and  designated  as indicated on
Schedule A to this letter (the "Shares").

     In connection  with rendering the opinions set forth below, I have examined
the PEA; the Company's  Articles of  Incorporation,  Articles  Supplementary and
Bylaws,  as reflected in the Company's  corporate  records;  resolutions  of the
Board of Directors of the Company relating to the  authorization and issuance of
the Shares;  and such other  documents as I deemed  relevant.  In  conducting my
examination,  I have  assumed  the  genuineness  of all  signatures,  the  legal
capacity of all natural persons, the authenticity,  accuracy and completeness of
documents  purporting  to be originals  and the  conformity  to originals of any
copies of documents. I have not independently  established any facts represented
in the documents so relied on.

     I am a member of the Bar of the State of Missouri.  The opinions  expressed
in this letter are based on the facts in existence and the laws in effect on the
date hereof and are  limited to the laws (other than the  conflict of law rules)
of the State of Maryland  that in my experience  are normally  applicable to the
issuance of shares by registered  investment companies organized as corporations
under the law of that state and to the  Securities  Act of 1933, as amended (the
"1933 Act"),  the  Investment  Company Act of 1940, as amended (the "1940 Act"),
and the  regulations  of the  Securities  and  Exchange  Commission  (the "SEC")
thereunder. I express no opinion with respect to any other laws.

     Based upon and subject to the  foregoing and the  qualifications  set forth
below, it is my opinion that:

     1. The issuance of the Shares has been duly authorized by the Company.

     2. When issued and paid for upon the terms provided in the PEA,  subject to
compliance with the 1933 Act, the 1940 Act, and applicable state laws regulating
the offer and sale of securities,  and assuming the continued valid existence of
the Company under the laws of the State of Maryland,  the Shares will be validly
issued, fully paid and non-assessable.




American Century Mutual Funds, Inc.
September 27, 2007
Page 2



     For the  record,  it should be stated  that I am an  employee  of  American
Century Services, LLC, an affiliate of the Company's investment advisor.

     I hereby  consent  to the use of this  opinion  as an exhibit to the PEA. I
assume no obligation to advise you of any changes in the foregoing subsequent to
the effectiveness of the PEA. In giving my consent I do not thereby admit that I
am in the category of persons whose  consent is required  under Section 7 of the
1933 Act or the  rules  and  regulations  of the SEC  thereunder.  The  opinions
expressed herein are matters of professional judgment and are not a guarantee of
result.


                                     Very truly yours,


                                     /s/ Christine J. Crossley
                                     ------------------------------------
                                     Christine J. Crossley
                                     Corporate Counsel

CJC/dnh




                                   SCHEDULE A
                                   -----------


Series Name                                           Class Name
-----------                                           ----------

Balanced Fund                                         Investor
                                                      Institutional
                                                      Advisor

Capital Growth Fund                                   Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Capital Value Fund                                    Investor
                                                      Institutional
                                                      Advisor

Focused Growth Fund                                   Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Fundamental Equity Fund                               Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Giftrust Fund                                         Investor

Growth Fund                                           Investor
                                                      Institutional
                                                      Advisor
                                                      R
                                                      C

Heritage Fund                                         Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Mid Cap Growth Fund                                   Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

New Opportunities Fund                                Investor

New Opportunities II Fund                             Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

NT Growth                                             Institutional

NT Vista                                              Institutional

Select Fund                                           Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Small Cap Growth Fund                                 Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Ultra Fund                                            Investor
                                                      Institutional
                                                      A
                                                      B
                                                      C
                                                      R

Veedot Fund                                           Investor
                                                      Institutional

Vista Fund                                            Investor
                                                      Institutional
                                                      Advisor
                                                      C
                                                      R