SecProbe.io

Mail Stop 4720          November 23, 2009   Shintaro Asako Chief Financial Officer MediciNova, Inc. 4350 La Jolla Village Drive, Suite 950 San Diego, CA 92122
 Re: MediciNova, Inc.
  Registration Statement on Form S-3
  Filed November 13, 2009
  File No. 333-163116

Dear Mr Asako:
  We have conducted a limited review of  your filing.  Our review was limited to
legal issues and did not incl ude a review of the financia l statements and disclosures
related to accounting issues.  Where indica ted, we think you should revise your document
in response to these comments.  If you disagr ee, we will consider your explanation as to
why our comment is inapplicable or a revisi on is unnecessary.  Please be as detailed as
necessary in your explanation.  In some of our comments, we may ask you to provide us with information so we may better understand your disclosure.  Af ter reviewing this
information, we may raise additional comments.
Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comments or any other aspect of our review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Mr. Shintaro Asako, Chief Financial Officer
MediciNova, Inc.
November 23, 2009 Page 2   FORM S-3

Incorporation By Reference, page 26

1. Please revise this section to incorporate by reference the Form 8-K filed on
September 4, 2009 and the Form 8-K filed on November 17, 2009.  See Item 12(a)(2) of Form S-3.

* * *

As appropriate, please amend your regist ration statement in response to these
comments.  You may wish to provide us with marked copies of the amendment to expedite our review.  Please furnish a cove r letter with your amendment that keys your
responses to our comments and provides any requested information.  Detailed cover
letters greatly facilitate our review.  Please understand that we may have additional comments after reviewing your amendmen t and responses to our comments.
  We urge all persons who are responsible for the accuracy and adequacy of the disclosure in the filing to be certain that the filing includes all in formation required under
the Securities Act of 1933 and that they have  provided all information investors require
for an informed investment 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 ev ent 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 purs uant to delegated authority, declare the
filing effective, it does not foreclose th e 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 staff comments a nd the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the
federal securities laws of the United States.

Mr. Shintaro Asako, Chief Financial Officer
MediciNova, Inc.  November 23, 2009 Page 3    In addition, please be advi sed that the Division of En forcement has access to all
information you provide to the staff of the Di vision 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 conf irmation of the fact that t hose requesting acceleration are
aware of their respective re sponsibilities under the S ecurities Act of 1933 and the
Securities Exchange Act of 1934 as they rela te 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 ad equate 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 a dvance of the requested effective date.
   Please contact Nandini Ac harya at (202) 551-3495 or me at (202) 551-3715 with
any questions.
        S i n c e r e l y ,
           J e f f r e y  R i e d l e r          A s s i s t a n t  D i r e c t o r     cc: David E. Shulman, Esq.
Dechert LLP 1775 I Street, N.W. Washington, DC 20006