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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-12-31</periodOfReport>

    <dateOfOriginalSubmission>2016-01-05</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001052100</issuerCik>
        <issuerName>WADDELL &amp; REED FINANCIAL INC</issuerName>
        <issuerTradingSymbol>WDR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001330721</rptOwnerCik>
            <rptOwnerName>Avery Michael L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6300 LAMAR AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>OVERLAND PARK</rptOwnerCity>
            <rptOwnerState>KS</rptOwnerState>
            <rptOwnerZipCode>66202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>197466</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Avery's beneficial ownership as reported in Column 5 of his ownership report on Form 4 filed on January 5, 2016 did not reflect a transfer of 8,291 shares of common stock of the issuer to Mr. Avery's ex-wife pursuant to a domestic relations order.  Column 5 of this amendment to the January 5, 2016 Form 4 reflects Mr. Avery's beneficial ownership after giving effect to the transfer.  Mr. Avery no longer reports as beneficially owned any securities owned by his ex-wife.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Michael L. Avery</signatureName>
        <signatureDate>2016-02-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
