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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0000069499-05-000006.txt : 20050617
<SEC-HEADER>0000069499-05-000006.hdr.sgml : 20050617
<ACCEPTANCE-DATETIME>20050617171912
ACCESSION NUMBER:		0000069499-05-000006
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050615
FILED AS OF DATE:		20050617
DATE AS OF CHANGE:		20050617

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SISTO FRANK
		CENTRAL INDEX KEY:			0001260815

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09114
		FILM NUMBER:		05903870

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		3045985430

	MAIL ADDRESS:	
		STREET 1:		781 CHESTNUT RIDGE RD
		STREET 2:		PO BOX 4310
		CITY:			MORGANTOWN
		STATE:			WV
		ZIP:			26505

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001260815</rptOwnerCik>
            <rptOwnerName>SISTO FRANK</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>781 CHESTNUT RIDGE RD</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 4310</rptOwnerStreet2>
            <rptOwnerCity>MORGANTOWN</rptOwnerCity>
            <rptOwnerState>WV</rptOwnerState>
            <rptOwnerZipCode>26505</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.5555</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12806</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Emp Stock Option - Right to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.5555</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.5555</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2000-07-17</value>
            </exerciseDate>
            <expirationDate>
                <value>2006-07-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">In addition, the reporting person's indirect ownership through 401(k) holdings as of June 10, 2005 was 2,799 shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Frank R. Sisto</signatureName>
        <signatureDate>2005-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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