<PAGE>   1

================================================================================

                     SECURITIES AND EXCHANGE COMMISSION
                                
                           WASHINGTON, D.C.  20549
                            _____________________
                                
                                  FORM 10-K/A
                                
            Annual Report Pursuant to Section 13 or 15(d) of the
                     Securities and Exchange Act of 1934
                                
                  FOR FISCAL YEAR ENDED SEPTEMBER 30, 1995
                                
                                   0-14732
                          (Commission file number)

                          ADVANCED MAGNETICS, INC.
           (Exact name of registrant as specified in its charter)

                Delaware                             4-2742593
        (State of Incorporation)       (IRS employer identification number)

           725 Concord Avenue                           02138
        Cambridge, Massachusetts                     (ZIP Code)
 (Address of principal executive offices)

                               (617) 354-3929
                       (Registrant's telephone number)
                                
         Securities registered pursuant to Section 12(g) of the Act:
                   Common Stock, par value $.01 per share
                                
     Indicate by check mark whether the registrant (1) has filed
all reports required to be filed by Section 13 or 15(d) of the
Securities Exchange Act of 1934 during the preceding 12 months
(or for such shorter period that the registrant was required to
file such reports), and (2) has been subject to such filing
requirements for the past 90 days.

          Yes     X                No  _________
               -------

     Indicate by check mark if disclosure of delinquent filers
pursuant to Item 405 of Regulation S-K is not contained herein,
and will not be contained, to the best of registrant's knowledge,
in definitive proxy or information statements incorporated by
reference in Part III of this Form 10-K or any amendment to this
Form 10-K.  [  X  ]

     The aggregate market value of Common Stock held by non-
affiliates of the registrant at December 8, 1995 was
approximately $135,190,000, based upon the last reported sale
price of the Common Stock on The American Stock Exchange.  The
number of shares of the registrant's Common Stock outstanding at
December 8, 1995 was 6,754,328.

     Documents incorporated by reference:

          Portions of the Annual Report to Stockholders for the
          fiscal year ended September 30, 1995 are incorporated
          by reference into Parts II and IV hereof.

          Portions of the Company's Proxy Statement relating to
          the Company's Annual Meeting of Stockholders to be held
          on February 6, 1996 are incorporated by reference into

          Part III hereof.

================================================================================

<PAGE>   2


                           SIGNATURES
                                
     Pursuant to the requirements of Section 13 or 15(d) of the
Securities Exchange Act of 1934, the registrant has duly caused
this report to be signed on its behalf by the undersigned,
thereunto duly authorized.

                                   ADVANCED MAGNETICS, INC.

                                 By:  /s/ Jerome Goldstein
                                      ---------------------------------------
                                      Jerome Goldstein, Chairman of the Board
                                      of Directors, President and Treasurer

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


<TABLE>
<CAPTION>
           Name                         Title                                         Date
           ----                         -----                                         ----

<S>                             <C>                                             <C>
/s/ Jerome Goldstein            Chairman of the Board of                        December 22, 1995
- ----------------------------    Directors, President and Treasurer
Jerome Goldstein                (principal executive and financial officer)


/s/ Anthony P. Annese           Vice President-Finance                          December 22, 1995
- ----------------------------    (principal accounting officer)
Anthony P. Annese     

/s/ Thomas Coor                 Director                                        December 22, 1995
- ----------------------------
Thomas Coor


/s/ Leslie Goldstein            Director                                        December 22, 1995
- ----------------------------
Leslie Goldstein


/s/ Richard L. McIntire         Director                                        December 22, 1995
- ----------------------------
Richard L. McIntire


/s/ Edward B. Roberts           Director                                        December 22, 1995
- ----------------------------
Edward B. Roberts


/s/Roger E. Travis              Director                                        December 22, 1995
- ----------------------------
Roger E. Travis


/s/ George M. Whitesides        Director                                        December 22, 1995
- ----------------------------
George M. Whitesides

</TABLE>



                                     -17-


<PAGE>   3


<TABLE>


                          EXHIBIT INDEX

<CAPTION>
Exhibit
Number                  Description                                                     Page
- -------                 -----------                                                     ----

   <S>       <C>
   3.1(1)    Certificate of Incorporation of the Company, as amended.
   
   3.2(2)    By-Laws of the Company, as amended.
   
   10.1(6)   1983 Stock Option Plan of the Company, as amended on 
             November 13, 1990.
   
   10.2(7)   1987 Employee Stock Purchase Plan.
   
   10.3(7)   1992 Employee Stock Purchase Plan.
   
   10.4(7)   1992 Non-Employee Director Stock Option Plan.
   
   10.5(9)   1993 Stock Plan.
   
   10.6(9)   1993 Non-Employee Director Stock Option Plan.
   
   10.7(3)   Technology Agreement dated January 21, 1983 between the 
             Company and Corning Glass Works (now Ciba Corning Diagnostics 
             Corp.) (confidential treatment previously granted).
   
   10.8(2)   Agreements between the Company and ML Technology Ventures, 
             L.P. dated as of March 23, 1987 (confidential treatment previously 
             granted).
   
   10.9(2)   Clinical Testing, Supply and Marketing Agreement between the 
             Company and Guerbet, S.A. dated May 22, 1987 (confidential 
             treatment previously granted).
   
   10.10(4)  Clinical Testing, Supply and Marketing Agreement between the 
             Company and Eiken Chemical Co., Ltd., dated August 30, 1988 
             (confidential treatment previously granted).
   
   10.11(5)  Contrast Agent Agreement dated between the Company and Guerbet, 
             S.A. dated September 29, 1989 (confidential treatment 
             previously granted).
   
   10.12(6)  Contrast Agent Agreement between the Company and Eiken 
             Chemical Co., Ltd. dated March 27, 1990 (confidential treatment 
             previously granted).
   
   10.13(6)  Amendment to Clinical Testing, Supply and Marketing Agreement 
             between the Company and Eiken Chemical Co., Ltd., dated 
             September 29, 1990 (confidential treatment previously granted).

</TABLE>


                                     -18-

<PAGE>   4
   


<TABLE>
   <S>       <C>
   10.14(6)  License, Supply and Marketing Agreement between the Company and
             Mallinckrodt Medical, Inc., dated June 28, 1990 (confidential 
             treatment previously granted).
   
   10.15(6)  Agreement of Amendment between the Company and ML 
             Technology Ventures, L.P. dated as of June 28, 1990.
   
   10.16(7)  Technology License Agreement between the Company and Squibb
             Diagnostics, dated February 5, 1991 (confidential treatment 
             previously granted).
   
   10.17(7)  AMI-227 License Agreement between the Company and Squibb
             Diagnostics, dated February 5, 1991 (confidential treatment 
             previously granted).
   
   10.18(7)  AMI-HS License Agreement between the Company and Squibb
             Diagnostics, dated February 5, 1991 (confidential treatment 
             previously granted).
   
   10.19(7)  Warrant Purchase Agreement between the Company and Squibb
             Diagnostics, dated February 11, 1991.
   
   10.20(7)  Purchase Agreement between the Company and ML Technology 
             Ventures, L.P., dated July 23, 1991.
   
   10.21(7)  Agreement of Amendment to Clinical Testing, Supply and 
             Marketing Agreement between the Company and Guerbet, S.A., dated 
             August 13, 1990.
   
   10.22(8)  Asset Purchase Agreement dated as of October 15, 1993 by and 
             between the Company and PerSeptive Biosystems, Inc.
   
   10.23(10) License, Supply and Marketing Agreement dated September 27, 1993
             between the Company and Sterling (confidential treatment previously
             granted).
   
   10.24(10) Termination Agreement dated November 8, 1993 between the 
             Company and Squibb Diagnostics (confidential treatment previously 
             granted).
   
   10.25(10) Amendment to License Agreement dated November 8, 1993 between 
             the Company and Squibb Diagnostics (confidential treatment 
             previously granted).
   
   10.26(11) Termination Agreement dated August 30, 1994 between the Company
             and Bristol-Myers Squibb Co.
   
   10.27(12) License and marketing agreement between the Company and Berlex
             Laboratories, Inc. dated as of February 1, 1995.

</TABLE>


                                     -19-

<PAGE>   5

  10.28 (12)    Supply Agreement between the Company and Berlex Laboratories, 
                Inc. dated as of February 1, 1995.

  11.1          Computation of earnings per share.

  13.1          1994 Annual Report

  23.1          Consent of Coopers & Lybrand L.L.P., independent accountants.

  27            Financial Data Schedule*
___________________

(1)     Incorporated herein by reference to the exhibits to the Company's 
        Registration Statement on Form S-8 (File No. 33-13953).

(2)     Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K for the fiscal year ended September 30, 1987.

(3)     Incorporated herein by reference to the exhibits to the Company's 
        Registration Statement on Form S-1 (File No. 33-5312).

(4)     Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K for the fiscal year ended September 30, 1988.

(5)     Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K for the fiscal year ended September 30, 1989.

(6)     Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K for the fiscal year ended September 30, 1990.

(7)     Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K for the fiscal year ended September 30, 1991.

(8)     Incorporated herein by reference to the exhibits to the Company's 
        Current Report on Form 8-K dated October 15, 1993.

(9)     Incorporated herein by reference to the exhibits to the Company's 
        definitive proxy statement for the fiscal year ended September 30, 1992.

(10)    Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K, as amended, for the fiscal year ended 
        September 30, 1993.

(11)    Incorporated herein by reference to the exhibits to the Company's 
        Annual Report on Form 10-K, for the fiscal year ended September 30, 
        1994.

(12)    Incorporated herein by reference to the exhibits to the Company's 
        Quarterly Report on Form 10-Q, for the fiscal quarter ended 
        December 31, 1994.


   *    Filed herewith
                                      -20-





<TABLE> <S> <C>

<ARTICLE> 5
<LEGEND>
THIS SCHEDULE CONTAINS SUMMARY FINANCIAL INFORMATION EXTRACTED FROM THE
FINANCIAL STATEMENTS OF ADVANCED MAGNETICS, INC. FOR THE YEAR ENDED SEPTEMBER
30, 1995, AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<MULTIPLIER> 1
<CURRENCY> US DOLLARS
       
<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          SEP-30-1995
<PERIOD-START>                             OCT-01-1994
<PERIOD-END>                               SEP-30-1995
<EXCHANGE-RATE>                                      1
<CASH>                                       1,066,419
<SECURITIES>                                36,561,263
<RECEIVABLES>                                5,884,542
<ALLOWANCES>                                         0
<INVENTORY>                                     55,567
<CURRENT-ASSETS>                            43,757,250
<PP&E>                                      12,083,997
<DEPRECIATION>                               5,143,097
<TOTAL-ASSETS>                              50,843,222
<CURRENT-LIABILITIES>                        1,772,150
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        67,534
<OTHER-SE>                                           0
<TOTAL-LIABILITY-AND-EQUITY>                50,843,222
<SALES>                                      2,120,457
<TOTAL-REVENUES>                             9,597,261
<CGS>                                          425,187
<TOTAL-COSTS>                               10,406,326
<OTHER-EXPENSES>                                     0
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                                   0
<INCOME-PRETAX>                              2,595,462
<INCOME-TAX>                                   400,000
<INCOME-CONTINUING>                                  0
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                      117,540
<NET-INCOME>                                 2,313,002
<EPS-PRIMARY>                                      .34
<EPS-DILUTED>                                        0
        

</TABLE>