-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 DO4NVJAc80di1O0Ka/nEd0BFdDlZQAgyE0JXFNnaWHfmDvC1FqcynTo/L+WCAHYu
 mPc6yxjN2Hl6IVpE/dFLEQ==

<SEC-DOCUMENT>0001179110-10-013899.txt : 20100916
<SEC-HEADER>0001179110-10-013899.hdr.sgml : 20100916
<ACCEPTANCE-DATETIME>20100916170008
ACCESSION NUMBER:		0001179110-10-013899
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100915
FILED AS OF DATE:		20100916
DATE AS OF CHANGE:		20100916

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OMACHINSKI DAVID L
		CENTRAL INDEX KEY:			0001215635

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-23357
		FILM NUMBER:		101076479

	MAIL ADDRESS:	
		STREET 1:		PO BOX 300
		CITY:			OSHKOSH
		STATE:			WI
		ZIP:			54903-0300

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BIOANALYTICAL SYSTEMS INC
		CENTRAL INDEX KEY:			0000720154
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-COMMERCIAL PHYSICAL & BIOLOGICAL RESEARCH [8731]
		IRS NUMBER:				351345024
		STATE OF INCORPORATION:			IN
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		2701 KENT AVE
		CITY:			WEST LAFAYETT
		STATE:			IN
		ZIP:			47906-1382
		BUSINESS PHONE:		3174634527

	MAIL ADDRESS:	
		STREET 1:		2701 KENT AVENUE
		CITY:			WEST LAFAYETTE
		STATE:			IN
		ZIP:			47906-1382
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-09-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000720154</issuerCik>
        <issuerName>BIOANALYTICAL SYSTEMS INC</issuerName>
        <issuerTradingSymbol>BASI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001215635</rptOwnerCik>
            <rptOwnerName>OMACHINSKI DAVID L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2701 KENT AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WEST LAFAYETTE</rptOwnerCity>
            <rptOwnerState>IN</rptOwnerState>
            <rptOwnerZipCode>47906-1382</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-09-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.90</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ Lina Reeves-Kerner, as attorney-in-fact for David Omachinski</signatureName>
        <signatureDate>2010-09-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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