BIOANALYTICAL SYSTEMS, INC.

EMPLOYEE INCENTIVE STOCK OPTION AGREEMENT

        THIS AGREEMENT, made this 1st day of April, 2004, by and between
Bioanalytical Systems, Inc., an Indiana corporation with its principal office at
2701 Kent Avenue, West Lafayette, Indiana (hereinafter called “Company”), and
Michael Cox, residing at 5521 Turkey Foot Road, Zionsville, IN 46077
(hereinafter called the “Grantee”), pursuant to the terms, conditions and
limitations contained in the Company’s 1997 Employee Incentive Stock Option Plan
(hereinafter called the “Plan”), a copy of which is attached hereto as Exhibit
A.

WITNESSETH THAT:

        WHEREAS, in the interests of affording an incentive to the Grantee to
give his best efforts to the Company as a key employee, the Company wishes to
provide that the Grantee shall have an option to buy Common Shares of the
Company:

        NOW, THEREFORE, it is hereby mutually agreed to as follows:

        1.        The Company hereby grants to the Grantee the right and option
to purchase, on the terms and conditions hereinafter set forth, all or any part
of an aggregate of 25,000 shares (hereinafter called “Subject Shares”) of the
presently authorized, but unissued, or treasury, Common Shares of the Company,
hereinafter called the “Common Shares”) at a purchase price of $4.58 per share,
exercisable in whole or in part from time to time subject to the limitation that
no option may be exercised with respect to fewer than twenty-five (25) shares
then subject to opinion hereunder, in which event any exercise must be as to all
such shares and subject to the further limitation that the options represented
by the Agreement shall be exercisable in two equal installments as set forth in
Section 6(e) of the Plan. The option may be exercised as to the shares covered
by the first installment from and after the first anniversary of the grant of
the option, with second installment becoming exercisable on the third
anniversary date. The option shall expire as to all shares subject to purchase
hereunder on the 10th anniversary date of this Agreement if not exercised on or
before such date.

        2.        Subject to the limitation specified in Section 1 hereof and in
Section 6(e) of the Plan the Grantee may from time to time exercise this option
by delivering a written notice of exercise and subscription agreement to the
Secretary of the Company specifying the number of whole shares to be purchased,
accompanied by payment (i) in cash, (ii) by certified check or bank cashier’s
check, (iii) through the tender to the Company of Common Shares of the Company
owned by the Optionee or by withholding of Common Shares of the Company that are
subject to the option, which Common Shares shall be valued, for purposes of
determining the extent to which the purchase price has been paid, at their fair
market value on the date of exercise as determined in Section 6(c) of the Plan,
or (iv) by a combination of the methods described in (i), (ii), or (iii). The
Company may, in its sole discretion, refuse to withhold Common Shares of the
Company as payment of the exercise price of the option. Such exercise shall be
effective upon receipt by the Secretary of such written notice, subscription
agreement and payment of the purchase price. Only the Grantee may exercise the
option during the lifetime of the Grantee. No fractional shares may be purchased
at any time hereunder.

        3.        Upon the effective exercise of the option, or any part
thereof, certificates representing the shares so purchased, marked fully paid
and non-assessable, shall be delivered to the person who exercised the option,
except as provided in Section 6(j) of the Plan. Until certificates representing
such shares shall have been issued and delivered, the Grantee shall not have any
of the rights or privileges of a shareholder of the Company in respect of any
such shares.

        4.        In the event that, prior to the delivery by the Company of all
the Subject Shares, there shall be an increase or reduction in the number of
Common Shares of the Company issued and outstanding by reason of any subdivision
or consolidation of Common Shares or any other capital adjustment, the number of
shares then subject to this option shall be increased or decreased as provided
in Section (g) of the Plan.

        5.        The option and the rights and privileges conferred by this
Option Agreement shall not be assigned or transferred by the Grantee in any
manner except by will or under the laws of descent and distribution. In the
event of any attempted assignment or transfer in violation of this Section 5,
the option, rights and privileges conferred by this Option Agreement shall
become null and void.

        6.        Nothing herein contained shall be deemed to create any
limitation nor restriction upon such rights as the Company would otherwise have
to terminate a person as an employee of the Company.

        7.        The option, rights and privileges herein conferred are granted
subject to the terms and conditions set forth herein and in the Plan.

        8.        Any notices to be given or served under the terms of this
Option Agreement shall be addressed to the Secretary of the Company at 2701 Kent
Avenue, West Lafayette, Indiana, and to the Grantee at the address set forth on
page one of this Option Agreement, or such other address or addresses as either
party may hereafter designate in writing to the other. Any such notice shall be
deemed to have been duly given or served, and deposited in the United States
mail.

        9.        The interpretation by the Incentive Stock Option Committee,
appointed by the Company’s Board of Directors to administer the Plan, or any
provisions of the Plan or of this Option Agreement shall be final and binding on
the Grantee unless otherwise determined by the Company’s Board of Directors.

        10.        This Option Agreement shall be governed by the laws of the
State of Indiana.

        IN WITNESS WHEREOF, the Company and the Grantee have signed this Option
Agreement as of the day and year first above written.

ATTEST:

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“COMPANY”

BIOANALYTICAL SYSTEMS, INC.

By:  

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“GRANTEE”

By:  

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