-----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>0001181075-06-000014.txt : 20061114
<SEC-HEADER>0001181075-06-000014.hdr.sgml : 20061114
<ACCEPTANCE-DATETIME>20061114170507
ACCESSION NUMBER:		0001181075-06-000014
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20061114
FILED AS OF DATE:		20061114
DATE AS OF CHANGE:		20061114

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COGENT COMMUNICATIONS GROUP INC
		CENTRAL INDEX KEY:			0001158324
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				522337274

	BUSINESS ADDRESS:	
		STREET 1:		1015 31ST STREET
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20007
		BUSINESS PHONE:		2022954200

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			PETERSON KENNETH D JR
		CENTRAL INDEX KEY:			0001181075

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31227
		FILM NUMBER:		061216490

	BUSINESS ADDRESS:	
		STREET 1:		2 BETHESDA METRO CTR
		STREET 2:		14TH FL
		CITY:			BETHESDA
		STATE:			MD
		ZIP:			20814
		BUSINESS PHONE:		3019516122

	MAIL ADDRESS:	
		STREET 1:		2 BETHESDA METRO CENTER
		STREET 2:		14TH FLOOR
		CITY:			BETHESDA
		STATE:			MD
		ZIP:			20814
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-11-14</periodOfReport>

    <issuer>
        <issuerCik>0001158324</issuerCik>
        <issuerName>COGENT COMMUNICATIONS GROUP INC</issuerName>
        <issuerTradingSymbol>COI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181075</rptOwnerCik>
            <rptOwnerName>PETERSON KENNETH D JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O COLUMBIA VENTURES CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>203 SE PARK PLAZA DRIVE, SUITE 270</rptOwnerStreet2>
            <rptOwnerCity>VANCOUVER</rptOwnerCity>
            <rptOwnerState>WA</rptOwnerState>
            <rptOwnerZipCode>98684</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3750</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2006-11-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>950000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.64</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1938965</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See  Footnote 3 below.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares held directly by Mr. Peterson.</footnote>
        <footnote id="F2">Represents shares held by Columbia Ventures Corporation.  Mr. Peterson is the Chief Executive Officer and sole shareholder of Columbia Ventures Corporation.</footnote>
        <footnote id="F3">On November 14, 2006, Columbia Ventures Corporation sold 950,00 shares of common stock pursuant to an underwritten transaction as part of a registered public offering of securities, Registration Statement number 333-133200.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kenneth D. Peterson, Jr.</signatureName>
        <signatureDate>2006-11-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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