-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 LLDnvNlXzxVbizuIUNr61lA1YzpmWTY8/ohVYc31y8oaJh6TrkegHu39rEgCwTPf
 WoklyMW1cjPykcXv58klrQ==

<SEC-DOCUMENT>0001070058-08-000001.txt : 20080428
<SEC-HEADER>0001070058-08-000001.hdr.sgml : 20080428
<ACCEPTANCE-DATETIME>20080428141656
ACCESSION NUMBER:		0001070058-08-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080424
FILED AS OF DATE:		20080428
DATE AS OF CHANGE:		20080428

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FEDERATED INVESTORS INC /PA/
		CENTRAL INDEX KEY:			0001056288
		STANDARD INDUSTRIAL CLASSIFICATION:	INVESTMENT ADVICE [6282]
		IRS NUMBER:				251111467
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		FEDERATED INVESTORS TOWER
		STREET 2:		5800 CORPORATE DR
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222
		BUSINESS PHONE:		4122888141

	MAIL ADDRESS:	
		STREET 1:		FEDERATED INVESTORS TOWER
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MURDY JAMES L
		CENTRAL INDEX KEY:			0001070058

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14818
		FILM NUMBER:		08780506

	BUSINESS ADDRESS:	
		STREET 1:		C/O FEDERATED INVESTORS TOWERS
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222-3779
		BUSINESS PHONE:		1-800-341-7400

	MAIL ADDRESS:	
		STREET 1:		1001 LIBERTY AVENUE
		STREET 2:		FEDERATED INVESTORS TOWER
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222-3779
</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>2008-04-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001056288</issuerCik>
        <issuerName>FEDERATED INVESTORS INC /PA/</issuerName>
        <issuerTradingSymbol>FII</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070058</rptOwnerCik>
            <rptOwnerName>MURDY JAMES L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1416 BEECHWOOD BLVD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15217</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>33.78</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-04-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-04-24</value>
            </exerciseDate>
            <expirationDate>
                <value>2018-04-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <remarks>The Power of Attorney dated July 26, 2006 is incorporated by reference.</remarks>

    <ownerSignature>
        <signatureName>/s/ Gail C. Jones (Attorney-in-Fact)</signatureName>
        <signatureDate>2008-04-28</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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