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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 VKSE1tCKdaYUTMDJpHc4Ng==

<SEC-DOCUMENT>0001126328-09-000316.txt : 20091020
<SEC-HEADER>0001126328-09-000316.hdr.sgml : 20091020
<ACCEPTANCE-DATETIME>20091020111620
ACCESSION NUMBER:		0001126328-09-000316
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091016
FILED AS OF DATE:		20091020
DATE AS OF CHANGE:		20091020

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PRINCIPAL FINANCIAL GROUP INC
		CENTRAL INDEX KEY:			0001126328
		STANDARD INDUSTRIAL CLASSIFICATION:	ACCIDENT & HEALTH INSURANCE [6321]
		IRS NUMBER:				421520346
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0224

	BUSINESS ADDRESS:	
		STREET 1:		711 HIGH STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50392-0300
		BUSINESS PHONE:		5152475111

	MAIL ADDRESS:	
		STREET 1:		711 HIGH STREET
		CITY:			DES MOINES
		STATE:			IA
		ZIP:			50392-0300

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			LAWLER JULIA M
		CENTRAL INDEX KEY:			0001213419

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-16725
		FILM NUMBER:		091127344
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-10-16</periodOfReport>

    <issuer>
        <issuerCik>0001126328</issuerCik>
        <issuerName>PRINCIPAL FINANCIAL GROUP INC</issuerName>
        <issuerTradingSymbol>PFG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001213419</rptOwnerCik>
            <rptOwnerName>LAWLER JULIA M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>711 HIGH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DES MOINES</rptOwnerCity>
            <rptOwnerState>IA</rptOwnerState>
            <rptOwnerZipCode>50392</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr VP &amp; Ch Invst Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-10-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25.8</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>25.8</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7300.2</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Security converts to common stock on a one-for-one basis.</footnote>
        <footnote id="F2">The reported phantom stock units were acquired pursuant to the Principal Select Savings Excess Plan and may be transferred at any time into another investment alternative under the Plan.  Interests under the Plan will be settled upon the reporting person's retirement or other termination of service.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Joyce N. Hoffman, by Power of Attorney</signatureName>
        <signatureDate>2009-10-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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