-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 TEEpDr8y5gAqFulpwJI2NGyRxswZOhCq/kpxR3R3EpwrK0UZiGrqeruABC1rlb+Q
 7HB4PKExyLC0inhXeH7OSg==

<SEC-DOCUMENT>0000069499-03-000042.txt : 20030807
<SEC-HEADER>0000069499-03-000042.hdr.sgml : 20030807
<ACCEPTANCE-DATETIME>20030807163648
ACCESSION NUMBER:		0000069499-03-000042
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030807
FILED AS OF DATE:		20030807

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MYLAN LABORATORIES INC
		CENTRAL INDEX KEY:			0000069499
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				251211621
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		1500 CORPORATE DRIVE
		STREET 2:		SUITE 400
		CITY:			CANONSBURG
		STATE:			PA
		ZIP:			15317
		BUSINESS PHONE:		724-514-1800

	MAIL ADDRESS:	
		STREET 1:		1500 CORPORATE DRIVE
		STREET 2:		SUITE 400
		CITY:			CANONSBURG
		STATE:			PA
		ZIP:			15317

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FRM CORP
		DATE OF NAME CHANGE:	19711003

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DELYNN LAURENCE
		CENTRAL INDEX KEY:			0001114444
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			0331

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09114
		FILM NUMBER:		03829077

	BUSINESS ADDRESS:	
		STREET 1:		2377 GULF OF MEXICO DR
		STREET 2:		UNIT 2 D-4
		CITY:			LONGBOAT KEY
		STATE:			FL
		ZIP:			34228
		BUSINESS PHONE:		9413830126

	MAIL ADDRESS:	
		STREET 1:		2377 GULF OF MEXICO DR
		STREET 2:		UNIT 2 D-4
		CITY:			LONGBOAT KEY
		STATE:			FL
		ZIP:			342228
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2003-08-07</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000069499</issuerCik>
        <issuerName>MYLAN LABORATORIES INC</issuerName>
        <issuerTradingSymbol>MYL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001114444</rptOwnerCik>
            <rptOwnerName>DELYNN LAURENCE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>113 MAPLE AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MORGANTOWN</rptOwnerCity>
            <rptOwnerState>WV</rptOwnerState>
            <rptOwnerZipCode>26501</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Mylan Laboratories Inc. Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-08-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.55</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>319000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

        <nonDerivativeTransaction>
            <securityTitle>
                <value>Mylan Laboratories Inc. Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2003-08-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.65</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>269000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>

    </nonDerivativeTable>



    <ownerSignature>
        <signatureName>Laurence S. DeLynn</signatureName>
        <signatureDate>2003-08-07</signatureDate>
    </ownerSignature>

</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----