SecProbe.io

Via Facsimile and U.S. Mail Mail Stop 6010                                                                                                   August 31, 2006
  Mr. Peter T. Kissinger President, Chairman and CEO Bioanalytical Systems, Inc. 2701 Kent Avenue West Lafayette, Indiana  47906
Re: Form 10-K for Fiscal Year Ended September 30, 2005
  Filed January 18, 2006
  Form 10-Q and 10-Q/A for the quarter ended June 30, 2006
 File No.  0-23357
Dear Mr. Kissinger:

We have reviewed your June 20, 2006 res ponse to our verbal comment issued
June 6, 2006 and have the following comments.   We have limited our review of your
Form 10-Q and Form 10-Q/A for the quart er ended June 30, 2006 to only the issues
addressed below and do not intend to expa nd our review to other portions of your
documents. In our comments, we ask you to provide us with information so we may better understand your disclosure.  Please be as de tailed as necessary in  your explanation.
After 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 on any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Form 10-Q and 10-Q/A for the six months ended June 30, 2006

Note 3. Intangible Assets and Impairment Loss
1. We noted that you recorded the cumulati ve amortization for the FDA compliant
facilities for the periods since acquis ition in the March 31, 2006 Form 10-Q.
Please address the following:
a) Tell us how you determined the fair value of the “non-employee intangible
asset” including whether or not you used an independent valuation expert.  In

Peter T. Kissinger
Bioanalytical Systems, Inc. August 31, 2006
Page 2 of 3
 your response also describe the valu ation technique and assumptions you
used.
b) Explain to us why you believe a ten year  life is appropriate for your “non-
employee intangible asset.”
c) We have read your SAB 99 analysis.  Explain to us why you believe a
revision to record the amor tization of your intangible a ssets in prior periods is
not material to net income.
d) Please address why you believe recordi ng the cumulative amortization in the
first quarter of 2006 would not have affected a “reasonable investor”.  We
note your stock price has decreased since you filed the Form 10-Q for the March 31, 2006.
e) Tell us whether or not your independ ent auditors concur with your SAB 99
analysis.
2. With regards to the impairment reco rded in the June 30, 2006 Form 10-Q/A,
please address the following:
a) Tell us why you believe the impairment  in the June 30, 2006 Form 10-Q was
recorded in the appropriate period.  Y ou state that the Baltimore clinic had
been experiencing losses since acqui sition. Provide us a chronology since
acquisition that led to re cording the impairment.
b) Clarify, in disclosure-type format, why the acquisition of a major customer by
a company that had other clinical stu dy providers and subsequent cancellation
of previously scheduled studies seriously impacted your current operating
results for PKLB. In this respect, also clarify if you had offsetting new
revenues from other customers.
c) Quantify for us the effect that the acquisition of a major customer by a
company that had other clin ical study providers, as referred to above, had on
your results of operations.
d) Clarify for us how much of the intangible asset that was reclassified to an
amortizable asset in the second quarter  of 2006 was written off in the third
quarter of 2006.
e) Provide us a detailed analysis of why the impairment amount and allocation as
reported in your Form 10-Q as origin ally filed changed in your 10-Q as
amended for the period ended June 30, 2006.
f) Provide us, in disclosure type format, the disclosures requ ired by paragraph 26
of SFAS 154.
g) You state that PKLB now constitutes your Baltimore c linical research unit.
Based on Item 1. Acquisitions in your Fo rm 10-K, PKLB also included a site
in Oregon and the United Kingdom.  Tell us  the status of those two sites and
clarify for us how you accounted for any goodwill or other intangible assets relating to those units and a ny associated impairments.

Peter T. Kissinger
Bioanalytical Systems, Inc. August 31, 2006
Page 3 of 3
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Please respond to this comment within 10 business days or tell us when you will
provide us with a response.  Please furnish a letter that keys your response to our
comment and provide the request ed information.  Detailed le tters greatly facilitate our
review.  Please file your letter on E DGAR under the form type label CORRESP.

You may contact Sasha Parikh, Sta ff Accountant, at (202) 551-3627  or Mary
Mast, Review Account ant, at (202) 551-3613  if you have questions regarding the
comments. In this regard, do not hesi tate to contact me, at (202) 551-3679.
        S i n c e r e l y ,            J i m  B .  R o s e n b e r g         Senior Assistant Chief Accountant