EXHIBIT 23.3


               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

We consent to the incorporation by reference in the Registration Statement on
Form S-8 and related Prospectus of Genzyme Corporation for the registration
of 235,870 shares of Genzyme Biosurgery Division common stock of our report
dated February 22, 2000, with respect to the consolidated financial
statements of GelTex Pharmaceuticals, Inc. included in its Annual Report
(Form 10-K) for the year ended December 31, 1999, filed with the Securities
and Exchange Commission.

                                                         /s/ Ernst & Young LLP

Boston, Massachusetts
July 25, 2001