-----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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<SEC-DOCUMENT>0000876883-06-000017.txt : 20060316
<SEC-HEADER>0000876883-06-000017.hdr.sgml : 20060316
<ACCEPTANCE-DATETIME>20060316172544
ACCESSION NUMBER:		0000876883-06-000017
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20060313
FILED AS OF DATE:		20060316
DATE AS OF CHANGE:		20060316

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MDC PARTNERS INC
		CENTRAL INDEX KEY:			0000876883
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ADVERTISING AGENCIES [7311]
		IRS NUMBER:				980364441
		STATE OF INCORPORATION:			A6
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		45 HAZELTON AVE
		CITY:			TORONTO
		STATE:			A6
		ZIP:			M5R 2E3
		BUSINESS PHONE:		646 429 1800

	MAIL ADDRESS:	
		STREET 1:		MDC PARTNERS INC. - LEGAL DEPT.
		STREET 2:		950 THIRD AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC CORP INC
		DATE OF NAME CHANGE:	20001204

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC COMMUNICATIONS CORP
		DATE OF NAME CHANGE:	19961028

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MDC CORPORATION
		DATE OF NAME CHANGE:	19950419

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ROSENBERG GRAHAM LAWRENCE
		CENTRAL INDEX KEY:			0001283583

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13718
		FILM NUMBER:		06693209

	MAIL ADDRESS:	
		STREET 1:		35 ABBEYWOOD TRAIL
		CITY:			TORONTO ONTARIO CANADA
		STATE:			A6
		ZIP:			999999999
</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>2006-03-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000876883</issuerCik>
        <issuerName>MDC PARTNERS INC</issuerName>
        <issuerTradingSymbol>MDCA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001283583</rptOwnerCik>
            <rptOwnerName>ROSENBERG GRAHAM LAWRENCE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MDC PARTNERS INC.</rptOwnerStreet1>
            <rptOwnerStreet2>45 HAZELTON AVENUE</rptOwnerStreet2>
            <rptOwnerCity>TORONTO</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>M5R 2E3</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Managing Director</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Subordinate Voting Shares</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Owned by spouse</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Financial Performance-Based Restricted Stock Units (Class A)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>35000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Subordinate Voting Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>65000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>100000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Subordinate Voting Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>32696</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.94</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>67304</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Subordinate Voting Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>26000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.4</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>93304</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Subordinate Voting Shares</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>26000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.53</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>67304</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-03-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>65000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2004-01-22</value>
            </exerciseDate>
            <expirationDate>
                <value>2007-01-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Subordinate Voting Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>65000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options</value>
                <footnoteId id="F4"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.4</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-03-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>26000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2002-10-09</value>
            </exerciseDate>
            <expirationDate>
                <value>2007-10-09</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Subordinate Voting Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>26000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.71</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-07-30</value>
            </exerciseDate>
            <expirationDate>
                <value>2007-07-30</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Subordinate Voting Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>13333</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13333</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.4</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-07-31</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-04-09</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class A Subordinate Voting Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>47625</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>47625</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">A portion of the Financial Performance-Based Restricted Stock Units (Class A Shares) of the Issuer may vest in each of 2007, 2008 and / or 2009 if the Issuer achieves specified performance targets in 2006 - 2008, and is dependent on continued employment.  Such financial targets are set forth in a &quot;Financial Performance-Based Restricted Stck Unit Agreement&quot;, a form of which was filed by the Issuer as an exhibit to a Form 8-K filed with the SEC on March 2, 2006.</footnote>
        <footnote id="F2">Canadian dollars.</footnote>
        <footnote id="F3">Stock Appreciation Rights (previously granted on January 22, 2003 or on July 30, 2003) vest 1/3 on each anniversary of the grant date, expire four years from the grant date, and are settled in cash or in stock, at the option of the Issuer.</footnote>
        <footnote id="F4">Stock Options (previously granted on October 9, 2002) vest 1/5 on grant and 1/5 on each anniversary of the grant date, expiring five years from the grant date.</footnote>
        <footnote id="F5">Stock Options (previously granted on July 31, 2003) are deemed to have fully vested on the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Graham L. Rosenberg</signatureName>
        <signatureDate>2006-03-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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