Mail Stop 3-9

							August 13, 2004


Stephen Cohen
Senior Vice President and Chief Financial Officer
Oscient Pharmaceuticals Corporation
100 Beaver Street
Waltham, Massachusetts 02453

Re:	Oscient Pharmaceuticals Corporation
Registration Statement on Form S-3
File Number 333-118026

Dear Mr. Cohen:

	We have performed a limited review of your registration
statement.  We note you have a pending confidential treatment
request.  Any issues that arise during our examination of the request
will need to be satisfied before we will consider your request for
acceleration of the effective date of the registration statement.

	We also note the disclosure in footnote (4) at the bottom of
page 54 stating that selling security holders may be identified in a
prospectus supplement.  Please note that unless they receive their
securities via transfer from someone who is identified in the filing
pre-effectively, any selling security holders will need to be
identified in a post-effective amendment.  Please revise the
disclosure accordingly.

	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 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.

	Please contact Greg Belliston at (202) 824-5219 or me at (202)
942-1840 with any questions.


							Sincerely,



							Jeffrey P. Riedler
							Assistant Director

cc:	Patrick O`Brien
	Ropes & Gray LLP
	One International Place
	Boston, Massachusetts 02110
Stephen Cohen
Oscient Pharmaceuticals Corporation
August 13, 2004
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