Exhibit 99.1

STATEMENT UNDER OATH OF PRINCIPAL EXECUTIVE OFFICER
REGARDING FACTS AND CIRCUMSTANCES
RELATING TO EXCHANGE ACT FILINGS

        I, Mark J. Levin, state and attest that:

        (1)    To the best of my knowledge, based upon a review of the covered reports of Millennium Pharmaceuticals, Inc. (the "Company"), and, except as corrected or supplemented in a subsequent covered report:

• no covered report contained an untrue statement of a material fact as of the end of the
period covered by such report (or in the case of a report on Form 8-K or definitive proxy
materials, as of the date on which it was filed); and

• no covered report omitted to state a material fact necessary to make the statements in the
covered report, in light of the circumstances under which they were made, not misleading
as of the end of the period covered by such report (or in the case of a report on Form 8-K
or definitive proxy materials, as of the date on which it was filed).

        (2)    I have reviewed the contents of this statement with the Company's audit committee.

        (3)    In this statement under oath, each of the following, if filed on or before the date of this statement, is a "covered report":

• the Company's Annual Report on Form 10-K for the fiscal year ended December 31,
2001 filed with the Securities and Exchange Commission;

• all reports on Form 10-Q, all reports on Form 8-K and all definitive proxy materials of
the Company filed with the Securities and Exchange Commission subsequent to the filing
of the Form 10-K identified above; and

• any amendments to any of the foregoing.

/s/    MARK J. LEVIN
Name:	Mark J. Levin  (Principal Executive Officer of Millennium Pharmaceuticals, Inc.)
Title:	Chairperson and Chief Executive Officer
Date:	August 13, 2002

Subscribed and sworn to
before me this 13th day of
August 2002.

/s/    JEAN L. ERNST

Notary Public

My Commission Expires: August 15,  2008