8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT
PURSUANT TO SECTION 13 OR 15(D)

OF THE SECURITIES EXCHANGE ACT OF 1934

DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED):

May 29, 2007

GENZYME CORPORATION

(Exact name of registrant as specified in its charter)

Massachusetts	0-14680	06-1047163
(State or other jurisdiction of incorporation or organization)	(Commission file number)	(IRS employer identification number)

500 Kendall Street, Cambridge, Massachusetts  02142

(Address of Principal Executive Offices)  (Zip Code)

Registrant’s telephone number, including area code:

(617) 252-7500

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o            Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o            Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o            Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o            Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01.  Other Events.

On May 29, 2007, Genzyme Corporation issued a press release announcing that its Board of Directors has authorized the Company to repurchase up to $1.5 billion or 20 million shares of its outstanding common stock over a three year period.  A copy of the press release is included as Exhibit 99.1 and incorporated by reference herein.

Item 9.01.  Financial Statements and Exhibits.

(d)  Exhibits:

Exhibit No.	Description
99.1	Press release of Genzyme Corporation dated May 29, 2007. Filed herewith.

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SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	GENZYME CORPORATION
Dated: May 29, 2007	By:	/s/ Michael S. Wyzga
		Michael S. Wyzga
		Executive Vice President and
		Chief Financial Officer

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EXHIBIT INDEX

Exhibit No.	Description
99.1	Press release of Genzyme Corporation dated May 29, 2007. Filed herewith.

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EX-99.1

Exhibit 99.1

For Immediate Release	Media Contact:	Investor Contact:
May 29, 2007	Dan Quinn	Sally Curley
	(617) 768-6849	(617) 768-6140

Genzyme Announces $1.5 Billion Share Repurchase Authorization

CAMBRIDGE, Mass. — Genzyme Corp. (Nasdaq: GENZ) announced today that its board of directors has authorized the repurchase of up to $1.5 billion or 20 million of the company’s outstanding common shares over the next three years.  The share repurchase program is designed to reduce the dilutive effect of the company’s equity compensation programs, and it reflects Genzyme’s confidence in the long-term value of its common stock.

Under the program, share purchases may be made from time to time on the open market, in privately negotiated transactions or by other means, at management’s discretion.  The manner of the purchases, the amount that the company spends and the number of shares it ultimately purchases will vary based on a range of factors, including share price.  The share repurchase program will be funded through operating cash flow and is expected to be accretive to Genzyme’s earnings per share.

This press release contains forward-looking statements, including statements regarding the repurchase of Genzyme’s common stock and the effect of the repurchases on Genzyme’s earnings.  These statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected in these forward-looking statements. These risks and uncertainties include, among others, market conditions, trading restrictions, alternative requirements for available cash and the risks and uncertainties described in our SEC reports filed under the Securities Exchange Act of 1934, including the factors discussed under the caption “Risk Factors” in Genzyme’s Quarterly Report on Form 10-Q for the period ended March 31, 2007.  We caution investors not to place undue reliance on the forward-looking statements

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contained in this document.  These statements speak only as of the date of this document and we undertake no obligation to update or revise the statements.

About Genzyme

One of the world’s leading biotechnology companies, Genzyme is dedicated to making a major positive impact on the lives of people with serious diseases.  Since 1981, the company has grown from a small start-up to a diversified enterprise with more than 9,000 employees in locations spanning the globe and 2006 revenues of $3.2 billion.  Genzyme has been selected by FORTUNE as one of the “100 Best Companies to Work for” in the United States.

With many established products and services helping patients in nearly 90 countries, Genzyme is a leader in the effort to develop and apply the most advanced technologies in the life sciences. The company’s products and services are focused on rare inherited disorders, kidney disease, orthopaedics, cancer, transplant, and diagnostic testing. Genzyme’s commitment to innovation continues today with a substantial development program focused on these fields, as well as immune disease, infectious disease, and other areas of unmet medical need.

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Genzyme’s press releases and other company information are available at www.genzyme.com and by calling Genzyme’s investor information line at 1-800-905-4369 within the United States or 1-703-797-1866 outside the United States.

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