-----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,
 MvaW//8D2ysduEMz1/28OvJzOEQQg/4eKsesOEqcW0qgolpHl983X69ZOEPJmx/R
 y310otui1dbOXAsFkf9HYQ==

<SEC-DOCUMENT>0001250842-08-000037.txt : 20080709
<SEC-HEADER>0001250842-08-000037.hdr.sgml : 20080709
<ACCEPTANCE-DATETIME>20080709121553
ACCESSION NUMBER:		0001250842-08-000037
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080627
FILED AS OF DATE:		20080709
DATE AS OF CHANGE:		20080709

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:			SMITH FREDERICK G
		CENTRAL INDEX KEY:			0001254012

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26076
		FILM NUMBER:		08944346

	MAIL ADDRESS:	
		STREET 1:		10706 BEAVER DAM RD
		CITY:			COCKEYSVILLE
		STATE:			MD
		ZIP:			21030
</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>2008-06-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001254012</rptOwnerCik>
            <rptOwnerName>SMITH FREDERICK G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>10706 BEAVER DAM RD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COCKEYSVILLE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21030</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-06-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.64</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>447835</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The purchase was a trade order executed by a broker.  This filing is done in accordance with the Response of the Office of Chief Counsel Division of Corporation Finance to the Society to the Corporate Secretaries &amp; Corporate Governance Professionals dated June 25, 2008.</footnote>
        <footnote id="F2">The purchase price is a weighted average for the purchase reported.  The range of prices for the purchase was $7.50 - $7.68.  The reporting person undertakes to provide, upon request by the Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares purchased at each separate price.</footnote>
        <footnote id="F3">Mr. Smith also directly owns 6,957,673  shares of Class B Common Stock and 4,338.88620 shares of Common Stock held by a 401(k) Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Lisa A. Olivieri, Esquire, on behalf of Frederick G. Smith, by Power of Attorney</signatureName>
        <signatureDate>2008-07-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----