EXHIBIT 99.2

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with this Quarterly Report of ImClone Systems Incorporated (the
"Company") on Form 10-Q for the period ending March 31, 2003 as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Michael
J. Howerton, Vice President, Finance and Business Development, Acting Chief
Financial Officer and Secretary of the Company, certify, pursuant to 18 U.S.C.
Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that:

    (1) The Report fully complies with the requirements of Section 13(a) or
        15(d) of the Securities Exchange Act of 1934; and

    (2) The information contained in the Report fairly presents, in all material
        respects, the financial condition and results of operations of the
        Company.

/s/   MICHAEL J. HOWERTON
- -----------------------------------------------------
Michael J. Howerton
Acting Chief Financial Officer
July 3, 2003

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