SecProbe.io

Mail Stop 4720       March 16, 2011
 Mr. Michael R. Cox Chief Financial Officer Bioanalytical Systems, Inc. 2701 Kent Avenue West Lafayette, Indiana 47906
Re: Bioanalytical Systems, Inc.
  Registration Statement on Form S-1
Amendment no. 1 filed March 14, 2011
  File No. 333-172508

Dear Mr. Cox:
 We have reviewed the amendment filed March 14, 2011 and have the following
comments.
 Please respond to this letter by amending your registration statement and providing the
requested information.  Where you do not beli eve our comments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.
 After reviewing any amendment to your re gistration statement and the information you
provide in response to these comments, we may have additional comments.

Cover Page

1. Please revise the cover page to indicate the preferred shares are redeemable.  In this
regard, we note the discussion under “Redemption” on page 13.

2. We note the statement that the preferred sh ares will not have a dividend rate but will
participate in any dividends payable upon comm on shares on an “as converted” basis.
We also note the disclosure under “Dividend Policy” on page 11 that you have not paid
any cash dividends and do not anticipate paying any cash dividends in the foreseeable future.  Please revise your cover page disclosure accordingly.

3. Please revise the disclosure to indicate th e range you anticipate th e conversion price per
share will be, for example, no less than 120% , nor more than 125%, of the market price
per share of your common stock on the prici ng date.  In addition, please indicate when
the pricing date will occur.

Mr. Michael R. Cox Bioanalytical Systems, Inc. March 16, 2011 Page 2

 4. Please expand the disclosure to indicate the ex tent to which there is a public market for
your Series A convertib le preferred stock.

We urge all persons who are responsible for th e accuracy and adequacy of the disclosure
in the filing to be certain that the filing incl udes the information the Securities Act of 1933 and
all applicable Securities Act rules require.  Since the company and its management are in
possession of all facts relating to a company’s disc losure, they are responsible for the accuracy
and adequacy of the disclosures they have made.
Notwithstanding our comments, in the event you request acceleration of  the effective date
of the pending registration statement please pr ovide a written statement from the company
acknowledging that:

 should the Commission or the staff, acting purs uant to delegated authority, declare the
filing effective, it does not foreclose the Co mmission 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.

Please refer to Rules 460 and 461 regarding re quests for acceleration.  We will consider a
written request for acceleration of  the effective date of the regi stration statement as confirmation
of the fact that those reques ting acceleration are aware of thei r respective responsibilities under
the Securities Act of 1933 and the Securities Excha nge Act of 1934 as they relate to the proposed
public offering of the securities specified in th e above registration stat ement.  Please allow
adequate time for us to review any amendment prior to the requested effective date of the
registration statement.
 You may contact John L. Krug, Senior Counsel, at (202) 551 -3862 or me at (202) 551-
3715 with any questions.
Sincerely,
     Jeffrey Riedler
Assistant Director
  cc: Stephen J. Hackman, Esq.