-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 JRkMXQO9m38gLqyRIT4N2A==

<SEC-DOCUMENT>0001209191-07-051247.txt : 20070830
<SEC-HEADER>0001209191-07-051247.hdr.sgml : 20070830
<ACCEPTANCE-DATETIME>20070830141131
ACCESSION NUMBER:		0001209191-07-051247
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070829
FILED AS OF DATE:		20070830
DATE AS OF CHANGE:		20070830

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KEITHLEY INSTRUMENTS INC
		CENTRAL INDEX KEY:			0000054991
		STANDARD INDUSTRIAL CLASSIFICATION:	INSTRUMENTS FOR MEAS & TESTING OF ELECTRICITY & ELEC SIGNALS [3825]
		IRS NUMBER:				340794417
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		28775 AURORA RD
		CITY:			SOLON
		STATE:			OH
		ZIP:			44139
		BUSINESS PHONE:		2162480400

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GAFFNEY ALAN S
		CENTRAL INDEX KEY:			0001232685

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09965
		FILM NUMBER:		071090736

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		4402480400

	MAIL ADDRESS:	
		STREET 1:		KEITHLEY INSTRUMENTS INC
		STREET 2:		28775 AURORA ROAD
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44139
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc4.xml
<DESCRIPTION>FORM 4 SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-08-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000054991</issuerCik>
        <issuerName>KEITHLEY INSTRUMENTS INC</issuerName>
        <issuerTradingSymbol>KEI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
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            <rptOwnerName>GAFFNEY ALAN S</rptOwnerName>
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        <reportingOwnerAddress>
            <rptOwnerStreet1>KEITHLEY INSTRUMENTS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>28775 AURORA ROAD</rptOwnerStreet2>
            <rptOwnerCity>SOLON</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44139</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
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        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP Comm Mkt &amp; Info Sys</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

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            <transactionDate>
                <value>2007-03-30</value>
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                <transactionPricePerShare>
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            <postTransactionAmounts>
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    <derivativeTable>
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            <expirationDate>
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                <underlyingSecurityTitle>
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                <underlyingSecurityShares>
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            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
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            <securityTitle>
                <value>Common Share Option</value>
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            <conversionOrExercisePrice>
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            <exerciseDate>
                <value>2002-04-06</value>
            </exerciseDate>
            <expirationDate>
                <value>2010-04-05</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
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            </postTransactionAmounts>
            <ownershipNature>
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            <exerciseDate>
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            <expirationDate>
                <value>2010-08-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>8000</value>
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            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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            <ownershipNature>
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        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
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            <conversionOrExercisePrice>
                <value>18.41</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-07-25</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2011-07-24</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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            <conversionOrExercisePrice>
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            <exerciseDate>
                <value>2004-07-24</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2012-07-23</value>
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            <underlyingSecurity>
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                <footnoteId id="F3"/>
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            <expirationDate>
                <value>2013-07-18</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                <underlyingSecurityShares>
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        <derivativeHolding>
            <securityTitle>
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            <conversionOrExercisePrice>
                <value>18.75</value>
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            <exerciseDate>
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                <footnoteId id="F4"/>
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            <expirationDate>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                <underlyingSecurityShares>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                <directOrIndirectOwnership>
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        <derivativeHolding>
            <securityTitle>
                <value>Common Share Option</value>
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                <value>14.00</value>
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                <value>2009-01-30</value>
                <footnoteId id="F2"/>
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            <expirationDate>
                <value>2017-01-30</value>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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        <derivativeHolding>
            <securityTitle>
                <value>Performance Award Unit</value>
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            <expirationDate>
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                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
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                    <footnoteId id="F5"/>
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                <sharesOwnedFollowingTransaction>
                    <value>4600</value>
                    <footnoteId id="F5"/>
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    </derivativeTable>

    <footnotes>
        <footnote id="F1">Acquired through Employee Stock Purchase and Dividend Reinvestment Plan.</footnote>
        <footnote id="F2">Date reported applies to 50% of total, one-half of the balance is then exercisable in each succeeding year</footnote>
        <footnote id="F3">Option became fully vested on August 10, 2005</footnote>
        <footnote id="F4">Option became fully vested on February 15, 2005</footnote>
        <footnote id="F5">Each Performance Award Unit represents the right to receive one common share at the end of the applicable performance period.  The number of units actually earned is subject to adjustment based upon the Company's revenue growth versus that of a defined Peer Group, as well as the Company maintaining an acceptable level of profitability.  Minimum number of units is 0 while the maximum number of units is two times the target number shown.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Mark J. Plush, Attorney-in Fact</signatureName>
        <signatureDate>2007-08-30</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----