<PAGE>   1

                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                 FORM 10-KSB/A-1


[X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE
    ACT OF 1934
                                       For the fiscal year ended April 30, 2000
                                       Commission File Number: 0-28666

                         AMERICAN BIO MEDICA CORPORATION
                 (Name of Small Business Issuer in its charter)

          New York                                       14-1702188
(State or other jurisdiction of               (IRS Employer Identification No.)
incorporation or organization)

            122 Smith Road                                 12106
         Kinderhook, New York                            (Zip Code)
(Address of principal executive offices)


Issuer's telephone number (800) 227-1243

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

         Securities registered pursuant to Section 12(g) of the Exchange Act:
Common Shares, $.01 par value per share

         Check  whether the issuer:  (1) filed all reports required to be filed
by Section 13 or 15(d) of the Exchange Act during the past 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.
[X] Yes  [  ] No

         Check if there is no disclosure of delinquent filers in response to
Item 405 of Regulation  S-B contained in this form, and no disclosure will 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-KSB
or any amendment to this Form 10-KSB.  [X]

         State issuer's revenues for its most recent fiscal year.  $7,653,000.

         The aggregate market value of 11,559,444 voting Common Shares held by
non-affiliates of the issuer was approximately $18,067,411 based on the last
reported sale price of the issuer's Common Shares, $.01 par value, as reported
on the Nasdaq SmallCap Market on July 12, 2000.

         The Proxy Statement for the Annual Meeting of Shareholders for the 2001
Fiscal Year has been incorporated herein by reference to the extent indicated
herein in Part III of this Form 10-KSB.

         As of July 12, 2000, the issuer had outstanding 18,045,548 Common
Shares, $.01 par value.

         Traditional Small Business Disclosure Format:  [   ]  [X] No


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ITEM 10. EXECUTIVE COMPENSATION

                           SUMMARY COMPENSATION TABLE

<TABLE>
<CAPTION>

                                         Annual Compensation                   Long-Term Compensation
                                   ----------------------------          -------------------------------------
                                                                                       Awards
                                                                          Restricted            Securities
Name and Principal Position        Year       Salary      Bonus          Stock Awards       Underlying Options
---------------------------        ----       ------      -----          ------------       ------------------
<S>                                <C>        <C>          <C>           <C>                  <C>
Stan Cipkowski                     2000       $96,000    $77,010         $        0              100,000
  Chairman, President              1999        96,000     64,992                  0                    0
  And Chief Executive Officer      1998        97,231     23,080                  0                    0

Jay Bendis                         2000       $84,000    $77,010                  0              100,000
  Vice-President Sales             1999        84,000     64,992                  0                    0
  And Marketing                    1998        85,077     23,080          2,356,000                    0

Douglas Casterlin                  2000       $84,000    $67,010                  0              100,000
  Vice-President Operations        1999        84,000     54,992                  0                    0
                                   1998        73,807     11,540            540,000                    0
</TABLE>


                        OPTION GRANTS IN LAST FISCAL YEAR

<TABLE>
<CAPTION>
                                                                                           Potential Realizable Value at
                                                                                           Assume Annual Rates of Stock
                                                                                                Price Appreciation
                              Individual Grants                                                 for Option Term(1)
                              -----------------                                            ------------------------------
                         Number of       Total Options
                         Securities        Granted to      Exercise
                         Underlying       Employees In       Price        Expiration
        Name          Options Granted    Fiscal Year(2)    ($/Share)        Date(3)             5%                10%
        ----          ---------------    --------------    ---------       --------            --                ---
<S>                       <C>                 <C>            <C>           <C>   <C>        <C>                <C>
Stan Cipkowski            100,000             6.8%           $2.50         11-22-09         $27,000            $212,000
Jay Bendis                100,000             6.8%           $2.50         11-22-09         $27,000            $212,000
Douglas Casterlin         100,000             6.8%           $2.50         11-22-09         $27,000            $212,000
</TABLE>

------------------------------
(1)  Potential realizable value is based on an assumption that the price of the
     Common Stock appreciates at the annual rate shown (compounded annually)
     from the date of grant until the end of the option term. These numbers are
     calculated based on the requirements of the Securities and Exchange
     Commission and do not reflect the Company's estimate of future stock price
     performance.

(2) The Company granted options representing 1,473,250 shares to employees in
    fiscal 2000.

(3) The options become exercisable in 25% increments on November 22, 1999.


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                      AGGREGATED OPTIONS EXERCISES IN LAST
                  FISCAL YEAR AND FISCAL YEAR END OPTION VALUES

<TABLE>
<CAPTION>

                                                                                           Value of Unexercised
                                                   Number of Unexercised Options         In-The-Money Options at
                                                         at Fiscal Year-End                   Fiscal Year-End
                                                   -----------------------------         -----------------------
                        Shares
                      Acquired on       Value
      Name             Exercise       Realized      Exercisable    Unexercisable    Exercisable     Unexercisable
      -----            --------       --------      -----------    -------------    -----------     -------------
<S>                       <C>           <C>           <C>             <C>              <C>             <C>
Stan Cipkowski            0             $  0          363,500         75,000           $  0            $  0
Jay Bendis                0                0          219,000         75,000              0               0
Douglas Casterlin         0                0          175,000         75,000              0               0
</TABLE>


                            COMPENSATION OF DIRECTORS

         Directors who are not employees or officers of the Company ("Outside
Directors") are granted an option to purchase 10,000 Common Shares at the time
of election and are granted an additional option to purchase 10,000 Common
Shares annually on the date of the Company's Annual Meeting of Shareholders.
Outside Directors are also granted an option to purchase 2,000 Common Shares for
service on the Audit Committee or the Compensation Committee annually on the
date of the Company's Annual Meeting of Shareholders. Outside Directors who
serve on both committees are granted an option to purchase 4,000 Common Shares
annually. Outside Directors receive a fee of $1,000 for attending meetings of
the Board, and are reimbursed for out-of-pocket expenses incurred in attending
such meetings.

                                       2

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         ITEM 12. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS

         At August 16, 2000, the Company had provided loans aggregating $415,000
to Stan Cipkowski, the Company's Chairman of the Board, President and Chief
Executive Officer. These loans are evidenced by a note and bear interest at the
rate of 11.5% per annum. The note is payable on demand. Mr. Cipkowski has agreed
to pledge 1,500,000 of the Company's Common Shares to the Company as collateral.
The Company's Board of Directors is currently evaluating forms of repayment of
this loan which may include cash repayment or repayment through the redemption
by the Company of certain of Mr. Cipkowski's Common Shares.

         The Company has collateralized a bank loan totaling $115,000 for Mr.
Cipkowski with a $112,000 certificate of deposit in the bank.

         As of August 16, 2000, the Company has provided a loan in the amount of
$380,000 to BioSys, Inc. ("BioSys"). BioSys is a development stage company
focusing on developing, manufacturing, marketing and selling proprietary new
products for the industrial microbiology testing market. Gerald Moore, a
director of the Company, is a stockholder and officer of BioSys. This loan is
convertible into shares of common stock of BioSys based on the percentage of the
funds provided by the Company through this loan during the two year period
ending July 14, 2001 compared to the total amount of funds provided to BioSys by
all other investors during this period. The Company's percentage ownership of
the outstanding shares of common stock of BioSys is limited to a maximum of 20%
based on a maximum of $400,000 that may be provided to BioSys by the Company.


                                       3

<PAGE>   5


SIGNATURES


         In accordance with Section 13 or 15(d) of the Exchange Act, the
registrant caused this report to be signed on its behalf by the undersigned,
thereunto duly authorized.

                                     AMERICAN BIO MEDICA CORPORATION


                                     By /s/ Stan Cipkowski
                                        -------------------------------------
                                        Stan Cipkowski, Chairman of the Board of
                                        Directors, President and Chief Executive
                                        Officer

Date:  November 10, 2000

         In accordance with the Exchange Act, this report has been signed below
by the following persons on behalf of the registrant and in the capacities
indicated on November 10, 2000:


/s/ Stan Cipkowski                    Chairman of the Board of  Directors,
----------------------------          President and Chief Executive Officer
Stan Cipkowski


/s/ Edmund Jaskiewicz                 Director
----------------------------
Edmund Jaskiewicz


/s/ Jay Bendis                        Director
----------------------------
Jay Bendis


/s/ Gerald Moore                      Director
----------------------------
Gerald Moore


/s/ Robert Aromando                   Director
----------------------------
Robert Aromando


/s/ Denis O'Donnell                   Director
----------------------------
Denis O'Donnell, M.D.


/s/ Keith Palmer                      Chief Financial Officer
----------------------------          (Principal Financial Officer)
Keith Palmer