-----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,
 WI6IsOkJ7dNE9tN98H6y06p/5Z5hxZK340uDYDlmJwWCbSQl2P4pjhsU9rL7N9tR
 1pq3m5TKwhcAYvptco69VQ==

<SEC-DOCUMENT>0001209191-03-012820.txt : 20030722
<SEC-HEADER>0001209191-03-012820.hdr.sgml : 20030722
<ACCEPTANCE-DATETIME>20030722110802
ACCESSION NUMBER:		0001209191-03-012820
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030722
FILED AS OF DATE:		20030722

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:			HOERSTEN MARK A
		CENTRAL INDEX KEY:			0001232686

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09965
		FILM NUMBER:		03795762

	BUSINESS ADDRESS:	
		STREET 1:		KEITHLEY INSTRUMENTS INC
		STREET 2:		28775 AURORA ROAD
		CITY:			CLEVELAND
		STATE:			OH
		ZIP:			44139
		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>X0101</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-07-22</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000054991</issuerCik><issuerName>KEITHLEY INSTRUMENTS INC</issuerName>        <issuerTradingSymbol>KEI</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001232686</rptOwnerCik><rptOwnerName>HOERSTEN MARK A</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>  </rptOwnerStreet1><rptOwnerStreet2>  </rptOwnerStreet2><rptOwnerCity>  </rptOwnerCity><rptOwnerState>  </rptOwnerState><rptOwnerZipCode>  </rptOwnerZipCode></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>VP Business Management</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Common Shares</value></securityTi
tle><transactionDate><value>2003-06-30</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1" /></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>4</value></transactionShares><transactionValue><value>14.38</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1568</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeSecurity><derivativeSecurity><securityTitle><value>Common Share Option</value></securityTitle><conversionOrExercisePrice><value>16.12</value></conversionOrExercisePrice><transactionDate><value>2003-07-18</value></transacti
onDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>30000</value></transactionShares><transactionValue><value>0</value></transactionValue><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2005-07-19</value><footnoteId id="F2" /></exerciseDate><expirationDate><value>2013-07-18</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Shares</value></underlyingSecurityTitle><underlyingSecurityShares><value>30000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>30000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></owne
rshipNature></derivativeSecurity><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></footnotes><ownerSignature><signatureName>Mark J. Plush, Attorney-in Fact</signatureName><signatureDate>2003-07-22</signatureDate></ownerSignature></ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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