-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 C8md+fE7lT4uceGQEiRYz/4qMPk+jZMTOP2AEd11k0tcwl1GnesmRc+qz8CbAQzG
 7EoDHbsF9blBHPDVk2F9/w==

<SEC-DOCUMENT>0001078201-10-000005.txt : 20100520
<SEC-HEADER>0001078201-10-000005.hdr.sgml : 20100520
<ACCEPTANCE-DATETIME>20100520200559
ACCESSION NUMBER:		0001078201-10-000005
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100518
FILED AS OF DATE:		20100520
DATE AS OF CHANGE:		20100520

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DEBOOM FRED A
		CENTRAL INDEX KEY:			0001078201

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-26068
		FILM NUMBER:		10849241

	MAIL ADDRESS:	
		STREET 1:		500 NEWPORT CENTER DRIVE
		STREET 2:		7TH FLOOR
		CITY:			NEWPORT BEACH
		STATE:			CA
		ZIP:			92660

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ACACIA RESEARCH CORP
		CENTRAL INDEX KEY:			0000934549
		STANDARD INDUSTRIAL CLASSIFICATION:	PATENT OWNERS & LESSORS [6794]
		IRS NUMBER:				954405754
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		500 NEWPORT CENTER DRIVE
		STREET 2:		7TH FLOOR
		CITY:			NEWPORT BEACH
		STATE:			CA
		ZIP:			92660
		BUSINESS PHONE:		9494808300

	MAIL ADDRESS:	
		STREET 1:		500 NEWPORT CENTER DRIVE
		STREET 2:		#
		CITY:			NEWPORT BEACH
		STATE:			CA
		ZIP:			92660
</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>2010-05-18</periodOfReport>

    <issuer>
        <issuerCik>0000934549</issuerCik>
        <issuerName>ACACIA RESEARCH CORP</issuerName>
        <issuerTradingSymbol>ACTG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001078201</rptOwnerCik>
            <rptOwnerName>DEBOOM FRED A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 NEWPORT CENTER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>7TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEWPORT BEACH</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92660</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-18</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2642</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>41767</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Grant of Restricted Stock Units</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Fred A. deBoom</signatureName>
        <signatureDate>2010-05-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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