Mail Stop 6010	November 28, 2005

Mr. Stephen Cohen
Senior Vice President and Chief Financial Officer
Oscient Pharmaceuticals Corp.
1000 Winter Street, Suite 2200
Waltham, Massachusetts 02451

Re:  	Oscient Pharmaceuticals Corp.
	Post-Effective Amendment No. 6 to Registration Statement on
Form
S-3,
      filed November 16, 2005
File No. 333-118026

Dear Mr. Cohen:

      We have limited our review of the above referenced
registration
statement to the disclosure with respect to the selling
stockholders.
In that respect, we have the following comment:

Please revise your prospectus to identify the selling stockholders
who are registered broker-dealers as underwriters with respect to
the
securities being offered.

      We urge all persons who are responsible for the accuracy and
adequacy of the disclosure in the filings reviewed by the staff to
be
certain that they have provided all information investors require
for
an informed decision.  Since the company and its management are in
possession of all facts relating to a company`s disclosure, they
are
responsible for the accuracy and adequacy of the disclosures they
have made.

	Notwithstanding our comments, in the event the company
requests
acceleration of the effective date of the pending registration
statement, it should furnish a letter, at the time of such
request,
acknowledging that:

	?	should the Commission or the staff, acting pursuant to
delegated authority, declare the filing effective, it does not
foreclose the Commission from taking any action with respect to
the
filing;

?	the action of the Commission or the staff, acting pursuant to
delegated authority, in declaring the filing effective, does not
relieve the company from its full responsibility for the adequacy
and
accuracy of the disclosure in the filing; and

?	the company may not assert this action as a defense in any
proceeding initiated by the Commission or any person under the
federal securities laws of the United States.

	In addition, please be advised that the Division of
Enforcement
has access to all information you provide to the staff of the
Division of Corporation Finance in connection with our review of
your
filing or in response to our comments on your filing.

      We will consider a written request for acceleration of the
effective date of the registration statement as a confirmation of
the
fact that those requesting acceleration are aware of their
respective
responsibilities under the Securities Act of 1933 and the
Securities
Exchange Act of 1934 as they relate to the proposed public
offering
of the securities specified in the above registration statement.
We
will act on the request and, pursuant to delegated authority,
grant
acceleration of the effective date.

      We direct your attention to Rules 460 and 461 regarding
requesting acceleration of a registration statement.  Please allow
adequate time after the filing of any amendment for further review
before submitting a request for acceleration.  Please provide this
request at least two business days in advance of the requested
effective date.

 	Please direct any questions to Sonia Barros at (202) 551-
3655.

         	               					Sincerely,



                	          					Jeffrey
Riedler
                           					Assistant
Director

cc:	Patrick O`Brien, Esq.
      Ropes & Gray LLP
      One International Place
      Boston, Massachusetts 02110

??

??

??

??

Mr. Stephen Cohen
November 28, 2005
Page 1