PRAECIS PHARMACEUTICALS INCORPORATED Stockholders Authorize Reverse Stock Split; Board Sets 1-for-5 Split Ratio

PRAECIS PHARMACEUTICALS INCORPORATED (NASDAQ: PRCS)
announced that at the special meeting held today, its stockholders
authorized PRAECIS' board of directors to effect a reverse stock split
of the Company's common stock. The Company also announced that its
board of directors has authorized implementation of a reverse stock
split at a ratio of 1-for-5, which the Company expects to take effect
after the close of trading on Tuesday, November 1, 2005.

   In the reverse split, each 5 shares of PRAECIS' issued and
outstanding common stock will automatically be combined into and
become one share of common stock. No fractional shares will be issued
in connection with the reverse stock split, and holders of fractional
shares will receive cash in lieu of their fractional shares. After
giving effect to the reverse split, the Company will have
approximately 10.5 million shares outstanding, subject to reduction
for fractional shares. The reverse split will affect all shares of
PRAECIS' common stock, including those shares underlying stock options
outstanding immediately prior to the effective time of the reverse
split.

   PRAECIS anticipates that its common stock will begin trading on a
split-adjusted basis when trading opens on Wednesday, November 2,
2005, with the interim ticker symbol "PRCSD." After 20 days, the
Company expects that the "D" designation will be removed, and its
ticker symbol will revert back to "PRCS." PRAECIS' transfer agent,
American Stock Transfer and Trust Company, will mail instructions to
stockholders of record as of the close of business on November 1, 2005
regarding the exchange of certificates for common stock.

   About PRAECIS

   PRAECIS PHARMACEUTICALS INCORPORATED is a biopharmaceutical
company focused on the discovery, development and commercialization of
innovative therapies that either address unmet medical needs or offer
improvements over existing therapies. PRAECIS has a novel MetAP-2
inhibitor in clinical development for non-Hodgkin's lymphoma and solid
tumors, as well as an innovative drug discovery technology, Direct
Select(TM), which enables the generation and practical use of
ultra-large libraries for the discovery of orally active compounds for
drug development. PRAECIS has received approval to market Plenaxis(R)
in both the United States and Germany.

   Plenaxis(R) is a registered trademark of PRAECIS PHARMACEUTICALS
INCORPORATED.