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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 OMWMEFrRO1NIuhC57smqrdIu1j0HVQYGHdZZxaDgsIfWPl/ynvBUiBIasYbuqM/g
 3YLvLadsmI9968sxvz5XEA==

<SEC-DOCUMENT>0001140361-07-011965.txt : 20070607
<SEC-HEADER>0001140361-07-011965.hdr.sgml : 20070607
<ACCEPTANCE-DATETIME>20070607170222
ACCESSION NUMBER:		0001140361-07-011965
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070605
FILED AS OF DATE:		20070607
DATE AS OF CHANGE:		20070607

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			PDI INC
		CENTRAL INDEX KEY:			0001054102
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		IRS NUMBER:				222919486
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		SADDLE RIVER EXECUTIVE CENTRE
		STREET 2:		1 ROUTE 17 SOUTH
		CITY:			SADDLE RIVER
		STATE:			NJ
		ZIP:			07458
		BUSINESS PHONE:		2012588450

	MAIL ADDRESS:	
		STREET 1:		SADDLE RIVER EXECUTIVE CENTRE
		STREET 2:		1 ROUTE 17 SOUTH
		CITY:			SADDLE RIVER
		STATE:			NJ
		ZIP:			07458

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PROFESSIONAL DETAILING INC
		DATE OF NAME CHANGE:	19980129

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SULLIVAN STEPHEN J
		CENTRAL INDEX KEY:			0001229881

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	333-46321
		FILM NUMBER:		07907418

	BUSINESS ADDRESS:	
		STREET 1:		C/O COVANCE INC
		STREET 2:		210 CARNEGIE CENTER
		CITY:			PRINCETON
		STATE:			NJ
		ZIP:			08540

	MAIL ADDRESS:	
		STREET 1:		210 CARNEGIE CENTER
		CITY:			PRINCETON
		STATE:			NJ
		ZIP:			08540
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-06-05</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001054102</issuerCik>
        <issuerName>PDI INC</issuerName>
        <issuerTradingSymbol>PDII</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001229881</rptOwnerCik>
            <rptOwnerName>SULLIVAN STEPHEN J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O PDI, INC., 1 ROUTE 17 SOUTH</rptOwnerStreet1>
            <rptOwnerStreet2>SADDLE RIVER EXECUTIVE CENTRE</rptOwnerStreet2>
            <rptOwnerCity>SADDLE RIVER</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07458</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2007-06-05</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4411</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>10.20</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8108</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.50</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-09-22</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>11.49</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-06-07</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On June 5, 2007, the date of the Company's annual meeting of stockholders, Mr. Sullivan was granted 4,411 restricted shares of common stock, one-third of which vest on June 5, 2008, June 5, 2009 and June 5, 2010.</footnote>
        <footnote id="F2">Includes 1,082 and 1,083 restricted shares of common stock that vest on 6/6/08 and 6/6/09, respectively.</footnote>
        <footnote id="F3">Currently exercisable.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Stephen J. Sullivan</signatureName>
        <signatureDate>2007-06-07</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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