Exhibit 23.1

CONSENT OF INDEPENDENT AUDITORS

We consent to the incorporation by reference in the Registration Statements on Form S-3 (Nos. 333-51772 and 333-90491) and in the related Prospectuses and on Form S-8 (Nos. 333-82221, 333-19915, 333-19917 and 333-59910) pertaining to the 1993 Long-Term Incentive Plan, as Amended and Restated, the 1993 Long-Term Incentive Plan, the 1993 Non-Employee Director Stock Option Plan and the 2001 Non-Officer, Non-Director Stock Incentive Plan of our report dated February 8, 2002, with respect to the consolidated financial statements of Transkaryotic Therapies, Inc. included in the Annual Report (Form 10-K) for the year ended December 31, 2001.

	/s/ Ernst & Young LLP
Boston, Massachusetts
March 26, 2002