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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,
 DmG0fwr6rchmXLskCFGYHQ0QLnd0sxnvMHFi65clZyjO+Uz0zBq1vJO0E3irsoD/
 FWm4+5f9EzeHzgWyQRVU3w==

<SEC-DOCUMENT>0001209191-03-021040.txt : 20030911
<SEC-HEADER>0001209191-03-021040.hdr.sgml : 20030911
<ACCEPTANCE-DATETIME>20030911101843
ACCESSION NUMBER:		0001209191-03-021040
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030909
FILED AS OF DATE:		20030911

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:			HUDSON WILLIAM J
		CENTRAL INDEX KEY:			0001059467
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRONIC CONNECTORS [3678]
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09965
		FILM NUMBER:		03891075

	BUSINESS ADDRESS:	
		STREET 1:		C/O CARPENTER TECHNOLOGY CORP
		STREET 2:		1047 NORTH PARK ROAD
		CITY:			WYOMISSING
		STATE:			PA
		ZIP:			19610
		BUSINESS PHONE:		6102082673

	MAIL ADDRESS:	
		STREET 1:		1047 NORTH PARK ROAD
		CITY:			WYOMISSING
		STATE:			PA
		ZIP:			19610
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc4a.xml
<DESCRIPTION>FORM 4/A SUBMISSION
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4/A</documentType><periodOfReport>2003-09-09</periodOfReport><dateOfOriginalSubmission>2003-09-11</dateOfOriginalSubmission><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000054991</issuerCik><issuerName>KEITHLEY INSTRUMENTS INC</issuerName>        <issuerTradingSymbol>KEI</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001059467</rptOwnerCik><rptOwnerName>HUDSON WILLIAM J</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>KEITHLEY INSTRUMENTS, INC.</rptOwnerStreet1><rptOwnerStreet2>28775 AURORA ROAD</rptOwnerStreet2><rptOwnerCity>SOLON</rptOwnerCity><rptOwnerState>OH</rptOwnerState><rptOwnerZipCode>44139</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reporting
OwnerRelationship></reportingOwner><derivativeTable><derivativeHolding><securityTitle><value>Common Stock Option</value></securityTitle><conversionOrExercisePrice><value>10.7</value><footnoteId id="F1" /></conversionOrExercisePrice><exerciseDate><value>2003-08-16</value><footnoteId id="F1" /></exerciseDate><expirationDate><value>2013-02-15</value><footnoteId id="F1" /></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stk</value><footnoteId id="F1" /></underlyingSecurityTitle><underlyingSecurityShares><value>10000</value><footnoteId id="F1" /></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>10000</value><footnoteId id="F2" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeHolding><derivativeTransaction><securityTitle><value>Phantom Stock Units</value></securityTitle><conversionOrExercisePrice><v
alue>16.6375</value><footnoteId id="F1" /></conversionOrExercisePrice><transactionDate><value>2003-09-08</value><footnoteId id="F3" /></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1" /></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>268.95</value><footnoteId id="F1" /></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><footnoteId id="F4" /></exerciseDate><expirationDate><footnoteId id="F4" /></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stk</value><footnoteId id="F1" /></underlyingSecurityTitle><underlyingSecurityShares><value>268.95</value><footnoteId id="F1" /></underlyingSec
urityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>6262.55</value><footnoteId id="F5" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">No change made from original filing</footnote><footnote id="F2">AMENDED - Previously listed as dollars owned.  Correct listing is shares owned. </footnote><footnote id="F3">AMENDED - Transaction date was 09/08/2003 and not 09/09/2003.</footnote><footnote id="F4">The phantom stock units were accrued under the Keithley Instruments, Inc. Deferred Stock Plan and are to be settled in five installments of common stock upon retirement from the Board of the reporting person; retirement date is not yet known.</footnote><footnote id="F5">Phantom shares were acquired on various dates (beginning 07/19/1999) with prices ranging from $4.219 to $64.00.</footno
te></footnotes><remarks></remarks><ownerSignature><signatureName>Mark J. Plush, Attorney-in Fact</signatureName><signatureDate>2003-09-11</signatureDate></ownerSignature></ownershipDocument>

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