Exhibit 99.3

            PURSUANT TO SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002
        (SUBSECTIONS (A) AND (B) OF SECTION 1350, CHAPTER 63 OF TITLE 18,
                              UNITED STATES CODE)

Pursuant to section 906 of the Sarbanes-Oxley Act of 2002 (subsections (a) and
(b) of section 1350, chapter 63 of title 18, United States Code), each of the
undersigned officers of ARIAD Pharmaceuticals, Inc., a Delaware corporation (the
Company"), does hereby certify, to such officer's knowledge, that:

The Quarterly Report on Form 10-Q for the quarter ended March 31, 2003 (the
"Form 10-Q") of the Company fully complies with the requirements of section
13(a) or 15(d) of the Securities Exchange Act of 1934, and information contained
in the Form 10-Q fairly presents, in all material respects, the financial
condition and results of operations of the Company.

Date: May 13, 2003             /s/ Harvey J. Berger, M.D.
                               --------------------------------
                               Harvey J. Berger, M.D.
                               Chairman, Chief Executive Officer and President

Date: May 13, 2003             /s/ Edward M. Fitzgerald
                               ---------------------------------
                               Edward M. Fitzgerald
                               Senior Vice President and Chief Financial Officer

The foregoing certification is being furnished solely pursuant to Section 906 of
the Sarbanes-Oxley Act of 2002 (subsections (a) and (b) of Section 1350, Chapter
63 of title 18, United States code) and is not being filed as a separate
disclosure document.

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