-----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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 OPOPJc4G1HLig29ofvt57g==

<SEC-DOCUMENT>0000069499-04-000001.txt : 20040209
<SEC-HEADER>0000069499-04-000001.hdr.sgml : 20040209
<ACCEPTANCE-DATETIME>20040209183730
ACCESSION NUMBER:		0000069499-04-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040206
FILED AS OF DATE:		20040209

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SUNSERI PATRICIA
		CENTRAL INDEX KEY:			0001051093

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09114
		FILM NUMBER:		04579178

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

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

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>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-02-06</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001051093</rptOwnerCik>
            <rptOwnerName>SUNSERI PATRICIA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1500 CORPORATE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 400</rptOwnerStreet2>
            <rptOwnerCity>CANONSBURG</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15317</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Senior VP</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-02-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>757386</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-02-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>46700</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.1326</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>710686</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares in Box 4 were held indirectly by the reporting person; such shares were held, and sold, by a charitable remainder unit trust, of which (as previously reported) the reporting person and her husband are trustees.  In addition, the reporting person's indirect ownership through 401(k) holdings was 8,741 shares as of February 5, 2004.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Patricia Sunseri</signatureName>
        <signatureDate>2004-02-09</signatureDate>
    </ownerSignature>
</ownershipDocument>

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