<PAGE>
 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
 
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549
 
                               ---------------
 
                                  FORM 10-K/A
                       FOR ANNUAL AND TRANSITION REPORTS
                         PURSUANT TO SECTION 13 OR 15
                    OF THE SECURITIES EXCHANGE ACT OF 1934
 
[X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE
    ACT OF 1934
 
  FOR THE FISCAL YEAR ENDED DECEMBER 31, 1997
 
                                      OR
 
[_] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES
    EXCHANGE ACT OF 1934
 
                        COMMISSION FILE NUMBER 1-14342
 
                               ---------------
 
                               NOVA CORPORATION
            (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
                GEORGIA                                58-2209575
    (STATE OR OTHER JURISDICTION OF         (IRS EMPLOYER IDENTIFICATION NO.)
    INCORPORATION OF ORGANIZATION)   
 
 
   ONE CONCOURSE PARKWAY, SUITE 300,                      30328
           ATLANTA, GEORGIA                            (ZIP CODE)
    (ADDRESS OF PRINCIPAL EXECUTIVE
               OFFICES)
 
                                (770) 396-1456
              REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE:
 
                               ---------------
 
          SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT:
 
        Title of each class         Name of each exchange on which registered
 COMMON STOCK, $0.01 PAR VALUE PER           NEW YORK STOCK EXCHANGE
               SHARE
 
       SECURITIES REGISTERED PURSUANT TO SECTION 12(G) OF THE ACT: NONE
 
                               ---------------
 
  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 [_] 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 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. [_]
 
  As of March 19, 1998, the aggregate market value of the Common Stock of the
Company held by non-affiliates of the Company was approximately $162,011,000,
based upon the closing price of $28.5625 per share on the New York Stock
Exchange composite tape on such date. Non-affiliate ownership is calculated by
excluding all shares that may be deemed to be beneficially owned by executive
officers and directors, without conceding that all such persons are
"affiliates" for purposes of the federal securities laws. As of March 19,
1998, there were 29,110,147 shares of the Company's Common Stock outstanding.
 
                      DOCUMENTS INCORPORATED BY REFERENCE
 
  Certain information contained in the registrant's 1997 Annual Report to
Shareholders for the year ended December 31, 1997 is incorporated herein by
reference in Parts II and IV of this Annual Report on Form 10-K. Certain
information contained in the registrant's Proxy Statement for the 1998 Annual
Meeting of Shareholders to be held on May 20, 1998 is incorporated herein by
reference in Part III of this Annual Report on Form 10-K.
 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------------
<PAGE>
 
                                  SIGNATURES
 
  Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, as amended, the Company has duly caused this report to
be signed on its behalf by the undersigned, thereunto duly authorized on the
28th day of April, 1998.
 
                                                 /s/ Edward Grzedzinski
                                         By: __________________________________
                                           EDWARD GRZEDZINSKI CHAIRMAN OF THE
                                          BOARD, PRESIDENT AND CHIEF EXECUTIVE
                                                         OFFICER
 
  Pursuant to the requirements of the Securities Exchange Act of 1934, as
amended, this report has been signed by the following persons on behalf of the
Company and in the capacities indicated on April 28th, 1998.
 
              SIGNATURE                          TITLE
 
       /s/ Edward Grzedzinski          Director, Chairman of
-------------------------------------   the Board, President
         EDWARD GRZEDZINSKI             and Chief Executive
                                        Officer (Principal
                                        Executive Officer)
 
         /s/ James M. Bahin            Director, Vice Chairman
-------------------------------------   of the Board, Chief
           JAMES M. BAHIN               Financial Officer and
                                        Secretary (Principal
                                        Financial and
                                        Accounting Officer)
 
       /s/ Charles T. Cannada          Director
-------------------------------------
         CHARLES T. CANNADA
 
       /s/ Dr. James E. Carnes         Director
-------------------------------------
         DR. JAMES E. CARNES
 
      /s/ U. Bertram Ellis, Jr.        Director
-------------------------------------
        U. BERTRAM ELLIS, JR.
 
        /s/ Dr. Henry Kressel          Director
-------------------------------------
          DR. HENRY KRESSEL
 
         /s/ Joseph P. Landy           Director
-------------------------------------
           JOSEPH P. LANDY
 
   /s/ Maurice F. Terbrueggen, Jr.     Director
 
-------------------------------------
     MAURICE F. TERBRUEGGEN, JR.
 
                                      37