-----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,
 DbamQ9CnhLzOEfB62o0dCMMv/uETen07grjoOIUx1AJQaU1ZUzl+UYk6AgzsBDBO
 ZvfPSYFQXgv9rPqC5dEDig==

<SEC-DOCUMENT>0001250842-10-000050.txt : 20101216
<SEC-HEADER>0001250842-10-000050.hdr.sgml : 20101216
<ACCEPTANCE-DATETIME>20101216094327
ACCESSION NUMBER:		0001250842-10-000050
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101214
FILED AS OF DATE:		20101216
DATE AS OF CHANGE:		20101216

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 DAVID D
		CENTRAL INDEX KEY:			0001016817

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26076
		FILM NUMBER:		101255157

	MAIL ADDRESS:	
		STREET 1:		C/O SINCLAIR BROADCAST GROUP
		STREET 2:		2000 WEST 41ST ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21211-1420
</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>2010-12-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001016817</rptOwnerCik>
            <rptOwnerName>SMITH DAVID D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SINCLAIR BROADCAST GROUP</rptOwnerStreet1>
            <rptOwnerStreet2>10706 BEAVER DAM ROAD</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>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>206600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.2995</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The sale price is a weighted average for the sale reported. 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 mumber of shares sold at each separate price.</footnote>
        <footnote id="F2">The range of prices for the sale was $8.27-$8.30.</footnote>
        <footnote id="F3">The Reporting Person also directly owns 7,999,925.227 shares of Class B Common Stock and 6,493.434170 shares of Class A Common Stock held in a 401K Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Clinton R. Black IV, Esquire, on behalf of David D. Smith, by Power of Attorney</signatureName>
        <signatureDate>2010-12-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----