<Page>

                                                                    Exhibit 99.1

       CERTIFICATION BY THE CHIEF EXECUTIVE OFFICER PURSUANT TO 18 U.S.C.
       SECTION 1350, AS ADDED BY SECTION 906 OF THE SARBANES-OXLEY ACT OF
                                      2002


     I, Jim McAlpine, the Chief Executive Officer of Magna Entertainment Corp.
("MEC"), certify that:

(i) the Annual Report on Form 10-K of MEC for the year ended December 31, 2002
fully complies with the requirements of Section 13(a) or 15(d) of the Securities
Exchange Act of 1934; and

(ii) the information contained in such Annual Report fairly presents, in all
material respects, the financial condition and results of operations of MEC.


/s/Jim McAlpine
Jim McAlpine
Chief Executive Officer
Date: March 27, 2003

     A signed original of this written statement required by Section 906 has
been provided to Magna Entertainment Corp. and will be retained by Magna
Entertainment Corp. and furnished to the Securities and Exchange Commission or
its staff upon request.

                                        1