<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2010-07-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001051741</issuerCik>
        <issuerName>FIRST NIAGARA FINANCIAL GROUP INC</issuerName>
        <issuerTradingSymbol>FNFG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001496282</rptOwnerCik>
            <rptOwnerName>Rendulic Mark R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>726 EXCHANGE STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 618</rptOwnerStreet2>
            <rptOwnerCity>BUFFALO</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>14210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP, Western PA Regional Sales</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8885</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock granted in accordance with the Company's 2002 Long-Term Incentive Stock Benefit Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Ann M. Segarra, power of attorney  For: Mark Rendulic</signatureName>
        <signatureDate>2010-07-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
