SECURITIES AND EXCHANGE COMMISSION


                            Washington, DC 20549

                               AMENDMENT NO. 1
                                     ON
                                 FORM 10-K/A


                Annual Report Pursuant to Section 13 or 15(d)
                   of the Securities Exchange Act of 1934

For the year ended October 31, 2004             Commission file number 0-13880

                      ENGINEERED SUPPORT SYSTEMS, INC.
           (Exact name of Registrant as specified in its charter)

                  Missouri                                43-1313242
         (State of Incorporation)             (IRS Employer Identification No.)

   201 Evans Lane, St. Louis, Missouri                      63121
 (Address of principal executive offices)                 (Zip Code)

Registrant's telephone number including area code:  (314) 553-4000

Securities registered pursuant to Section 12(b) of the Securities Exchange
Act of 1934:  None

Securities registered pursuant to Section 12(g) of the Securities Exchange
Act of 1934:

                                                    Name of each exchange on
            Title of each class                         which registered
            -------------------                     ------------------------

       Common stock, $.01 par value                     Nasdaq National
                                                         Market System

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 requirement for the past 90 days.  Yes        No   X   .
                                                  -----     -------

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 the Registrant's knowledge, in the 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
                                         -----

Indicate by check mark whether the Registrant is an accelerated filer (as
defined in Rule 12b-2 of the Securities Exchange Act of 1934). 
Yes   X     No        .
    -----     -------


Based on the closing price on December 31, 2004, the aggregate market value
of the voting stock held by non-affiliates of the Registrant was
approximately $1,241,347,000.

The number of shares of the Registrant's common stock, $.01 par value,
outstanding at December 31, 2004 was 26,837,381.



                     DOCUMENTS INCORPORATED BY REFERENCE

  Parts I and II incorporate by reference portions of the Engineered Support
Systems, Inc. Annual Report to Shareholders (the Annual Report) for the year
ended October 31, 2004. Part III incorporates by reference portions of the
Engineered Support Systems, Inc. Proxy Statement for the Annual Shareholders
Meeting to be held on March 1, 2005 (the Definitive Proxy Statement) to be
filed within 120 days after the close of the year ended October 31, 2004.




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EXPLANATORY NOTE: This Amendment No. 1 on Form 10-K/A amends the Annual
----------------
Report on Form 10-K for the year ended October 31, 2004 (the "Form 10-K") of
Engineered Support Systems, Inc. (the "Company"), and is being filed solely
for the purpose of: (a) filing an amended Exhibit 13, and (b) reporting
certain information pursuant to Item 9B of Part II. As a result of these
amendments, the certifications filed as Exhibits 31 and 32 in Item 15 have
been re-executed as of the date of this Amendment No. 1 on Form 10-K/A.

This Amendment No. 1 on Form 10-K/A amends only the items stated above and
does not otherwise update disclosures for events that occurred subsequent to
the original filing date of the Form 10-K.



                                   PART II

ITEM 9B.          OTHER INFORMATION
--------          -----------------

         On November 1, 2004, the Company executed employment agreements
with Michael F. Shanahan, Sr., Gerald A. Potthoff, Gary C. Gerhardt and
Ronald W. Davis.

         Under the employment agreement with Michael F. Shanahan, Sr., Mr.
Shanahan Sr. will serve as the Company's Chairman of the Board for a term of
three years. Unless terminated by Mr. Shanahan upon not less than 90 days
nor more than 120 days written notice to the Company, or by the Company, the
employment agreement continues on a year-to-year basis. The current annual
base salary under this agreement is $1,000,000 and Mr. Shanahan also
receives an annual incentive bonus payment. If the agreement is terminated
by the Company, for other than cause, Mr. Shanahan is entitled to
termination pay equal to twice his total annual compensation (payable in 24
equal monthly payments) for the fiscal year of the Company ending
immediately prior to the date of termination. Mr. Shanahan is prohibited
from competing with the Company after termination during such time as he
continues to receive compensation from the Company. The employment agreement
further provides that he is entitled to an annual stock option award as
determined by the Compensation Committee of the Board of Directors. The
employment agreement also provides for deferred compensation to be paid in
the event of the retirement, disability or death of Mr. Shanahan. For
disability, the benefit is $52,500 per month for a maximum of 60 consecutive
months. For retirement or death, the benefit is $52,500 per month for 24
months. In the event of a change in control of the Company, Mr. Shanahan is
entitled to receive a lump sum cash payment in an amount equal to 2.99 times
his average annual compensation for the prior five fiscal years of
employment with the Company.

         Under the employment agreement with Gerald A. Potthoff, Mr.
Potthoff will serve as Vice Chairman, Chief Executive Officer and President
for a term of three years. Unless terminated by Mr. Potthoff upon not less
than 90 days nor more than 120 days written notice to the Company, or by the
Company, the employment agreement continues on a year-to-year basis. Under
the terms of Mr. Potthoff's employment agreement, Mr. Potthoff is paid a
base annual salary of $720,000 and receives an annual incentive bonus
payment. The employment agreement also provides that he is entitled to
receive an annual stock option award based on 15,000 shares of Company
common stock. If the agreement is terminated by the Company, other than for
cause, Mr. Potthoff is entitled to termination pay equal to his base salary
upon the date of termination payable over 12 months. The agreement prohibits
Mr. Potthoff from competing with the Company for a period of two years after
termination. In the event of a change in control of the Company, Mr.
Potthoff is entitled to receive a lump sum cash payment in an amount equal
to 2.99 times his average compensation for the prior five fiscal years of
employment with the Company.

         Under the employment agreement with Gary C. Gerhardt, Mr. Gerhardt
will serve as Vice Chairman and Chief Financial Officer for a term of three
years. Unless terminated by Mr. Gerhardt upon not less than 90 days nor more
than 120 days written notice to the Company, or by the Company, the


                                   - 3 -

employment agreement continues on a year-to-year basis. Under the terms of
Mr. Gerhardt's employment agreement, Mr. Gerhardt is paid a base annual
salary of $500,000 and receives an annual incentive bonus payment. The
employment agreement also provides that he is entitled to receive an annual
stock option award based on 15,000 shares of Company common stock. If the
agreement is terminated by the Company, other than for cause, Mr. Gerhardt
is entitled to termination pay equal to his base salary upon the date of
termination payable over 12 months. The agreement prohibits Mr. Gerhardt
from competing with the Company for a period of two years after termination.
In the event of a change in control of the Company, Mr. Gerhardt is entitled
to receive a lump sum cash payment in an amount equal to 2.99 times his
average annual compensation for the prior five fiscal years of employment
with the Company.

         Under the employment agreement with Ronald W. Davis, Mr. Davis will
serve as the Company's President, Business Development for a term of three
years. Unless terminated by Mr. Davis upon not less than 90 days nor more
than 120 days written notice to the Company, or by the Company, the
employment agreement continues on a year-to-year basis. Under the terms of
Mr. Davis' employment agreement, Mr. Davis is paid a base annual salary of
$440,000 and receives an annual incentive bonus payment. The employment
agreement also provides that he is entitled to receive an annual stock
option award based on 15,000 shares of Company common stock. If the
agreement is terminated by the Company, other than for cause, Mr. Davis is
entitled to termination pay equal to his base salary upon the date of
termination payable over 12 months. The agreement prohibits Mr. Davis from
competing with the Company for a period of two years after termination. In
the event of a change in control of the Company, Mr. Davis is entitled to
receive a lump sum cash payment in an amount equal to 2.99 times his average
annual compensation for the prior five fiscal years of employment with the
Company.



                                   PART IV

ITEM 15.          EXHIBITS, FINANCIAL STATEMENTS AND SCHEDULES
--------          --------------------------------------------

(3)      Exhibits.

         Lists of Exhibits (listed by numbers corresponding to exhibit table
         of Item 601 in Regulation S-K)

         13       Portions of the Engineered Support Systems, Inc. Annual
                  Report for the year ended October 31, 2004.

         23       Consent of PricewaterhouseCoopers LLP, Independent
                  Accountants

         31.1     Certification of Chief Executive Officer

         31.1     Certification of Chief Financial Officer

         32.1     Certification of Chief Executive Officer pursuant to
                  Section 906 of the Sarbanes-Oxley Act of 2002

         32.2     Certification of Chief Financial Officer pursuant to
                  Section 906 of the Sarbanes-Oxley Act of 2002



                                   - 4 -

                                 SIGNATURES

         Pursuant to the requirements of the Section 13 or 15 (d) of the
Securities Exchange Act of 1934, the Company has duly caused this Amendment
No. 1 on Form 10-K/A to be signed on its behalf by the undersigned,
thereunto duly authorized.

                                             ENGINEERED SUPPORT SYSTEMS, INC.

Dated:  February 1, 2005                     By: /s/ Gary C. Gerhardt
                                                 -----------------------------
                                                 GARY C. GERHARDT
                                                 Vice Chairman and Chief
                                                  Financial Officer






                                   - 5 -

                      ENGINEERED SUPPORT SYSTEMS, INC.

                                EXHIBIT INDEX


Lists of Exhibits (listed by numbers corresponding to exhibit table of Item
601 in Regulation S-K)

13       Portions of the Engineered Support Systems, Inc. Annual Report for
         the year ended October 31, 2004.

23       Consent of PricewaterhouseCoopers LLP, Independent Accountants

31.1     Certification of Chief Executive Officer

31.2     Certification of Chief Financial Officer

32.1     Certification of Chief Executive Officer pursuant to Section 906 of
         the Sarbanes-Oxley Act of 2002

32.2     Certification of Chief Financial Officer pursuant to Section 906 of
         the Sarbanes-Oxley Act of 2002



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