EXHIBIT 23.3

               CONSENT OF ERNST & YOUNG LLP, INDEPENDENT AUDITORS

We consent to the reference to our firm under the caption "Experts" in the
Registration Statement on Form S-3 and related Prospectus of Genzyme Corporation
for the registration of 358,100 shares of Genzyme Biosurgery Division common
stock and to the incorporation by reference therein 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
June 21, 2001