-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 OvdZKHXbrNcZLfxNlacCBt9S3HHSz629qL3wY+PuS9vU07M5QSNBgwdPcjszhBje
 1wmZBK5aSt8hLXywmV4+8w==

<SEC-DOCUMENT>0001250842-08-000055.txt : 20081017
<SEC-HEADER>0001250842-08-000055.hdr.sgml : 20081017
<ACCEPTANCE-DATETIME>20081017100738
ACCESSION NUMBER:		0001250842-08-000055
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20081015
FILED AS OF DATE:		20081017
DATE AS OF CHANGE:		20081017

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SINCLAIR BROADCAST GROUP INC
		CENTRAL INDEX KEY:			0000912752
		STANDARD INDUSTRIAL CLASSIFICATION:	TELEVISION BROADCASTING STATIONS [4833]
		IRS NUMBER:				521494660
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		10706 BEAVER DAM ROAD
		CITY:			HUNT VALLEY
		STATE:			MD
		ZIP:			21030
		BUSINESS PHONE:		4105681500

	MAIL ADDRESS:	
		STREET 1:		10706 BEAVER DAM ROAD
		CITY:			HUNT VALLEY
		STATE:			MD
		ZIP:			21030

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LEADER MARTIN R
		CENTRAL INDEX KEY:			0001248331

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26076
		FILM NUMBER:		081128482

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		703-524-0991

	MAIL ADDRESS:	
		STREET 1:		1318 ROUND OAK COURT
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22101
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-10-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000912752</issuerCik>
        <issuerName>SINCLAIR BROADCAST GROUP INC</issuerName>
        <issuerTradingSymbol>SBGI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001248331</rptOwnerCik>
            <rptOwnerName>LEADER MARTIN R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1318 ROUND OAK COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MCLEAN</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22101</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1719.7514</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.2559</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29716.6909</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Purchase reflects automatic reinvestment of quarterly cash dividend received.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Lisa A. Olivieri, Esquire on behalf of Martin R. Leader, by Power of Attorney</signatureName>
        <signatureDate>2008-10-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----