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

September 21, 2005

Date of Report (Date of earliest event reported)

PRAECIS PHARMACEUTICALS INCORPORATED

(Exact Name of Registrant as Specified in Charter)

Delaware		000-30289		04-3200305
(State or other Jurisdiction of Incorporation)		(Commission File No.)		(IRS Employer Identification No.)

830 Winter Street, Waltham, Massachusetts 02451-1420

(Address of principal executive offices, including zip code)

(781) 795-4100

(Registrant’s telephone number, including area code)

(Former Name or Former Address, if Changed Since Last Report)

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:

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 7.01. Regulation FD Disclosure.

On September 21, 2005, PRAECIS PHARMACEUTICALS INCORPORATED issued a press release announcing the presentation of preclinical data on its investigational compound, PPI-2458, at the Cambridge Healthtech Institute’s Inaugural Targeted Cancer Therapies Conference being held in Cambridge, Massachusetts. The Company’s presentation, entitled “Inhibitors of Methionine Aminopeptidase-2 (MetAP-2) in the Treatment of Non-Hodgkin’s Lymphoma,” was delivered by William Westlin, Ph.D., Vice President, Preclinical Research. A copy of the presentation is available on the Company’s website at http://www.praecis.com, under “Investors.”

Item 9.01. Financial Statements and Exhibits.

Exhibit 99.1 Press Release issued by PRAECIS PHARMACEUTICALS INCORPORATED on September 21, 2005.

SIGNATURES

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.

Date: September 21, 2005	PRAECIS PHARMACEUTICALS INCORPORATED


	By	/s/ Edward C. English
		Edward C. English
		Vice President, Chief Financial Officer, Treasurer and
		Assistant Secretary