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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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 PX7D4gNoNy3oLNuhML8dCg==

<SEC-DOCUMENT>0001461136-10-000018.txt : 20101213
<SEC-HEADER>0001461136-10-000018.hdr.sgml : 20101213
<ACCEPTANCE-DATETIME>20101213150224
ACCESSION NUMBER:		0001461136-10-000018
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101209
FILED AS OF DATE:		20101213
DATE AS OF CHANGE:		20101213

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LYDALL INC /DE/
		CENTRAL INDEX KEY:			0000060977
		STANDARD INDUSTRIAL CLASSIFICATION:	MOTOR VEHICLE PARTS & ACCESSORIES [3714]
		IRS NUMBER:				060865505
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE COLONIAL RD
		STREET 2:		P O BOX 151
		CITY:			MANCHESTER
		STATE:			CT
		ZIP:			06045-0151
		BUSINESS PHONE:		2036461233

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COLONIAL BOARD CO
		DATE OF NAME CHANGE:	19700115

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			ESTEY MONA G
		CENTRAL INDEX KEY:			0001282482

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-07665
		FILM NUMBER:		101247677
</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>2010-12-09</periodOfReport>

    <issuer>
        <issuerCik>0000060977</issuerCik>
        <issuerName>LYDALL INC /DE/</issuerName>
        <issuerTradingSymbol>LDL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001282482</rptOwnerCik>
            <rptOwnerName>ESTEY MONA G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O LYDALL, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>ONE COLONIAL ROAD, P.O. BOX 151</rptOwnerStreet2>
            <rptOwnerCity>MANCHESTER</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06045-0151</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Human Resources</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>29647</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.80</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-12-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2011-12-10</value>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <value>2020-12-09</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>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents an award of Performance Shares granted under the Company's 2003 Stock Incentive Compensation Plan, which award is subject to a substantial risk of forfeiture and vests, if at all, to the extent determined upon the certification by the Compensation Committee of the Board of Directors of the Company that the Company has achieved certain specified financial performance criteria during the one-year period ending December 31, 2013.</footnote>
        <footnote id="F2">Includes (i) 2,125 unvested shares subject to time-based restricted stock awards and (ii) 16,000 unvested shares subject to a performance-based restricted stock award.</footnote>
        <footnote id="F3">Incentive stock options granted under the Amended and Restated Lydall 2003 Stock Incentive Compensation Plan.  Options become exercisable at the rate of 25% per year, beginning one year from initial grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Paul G. Igoe, Attorney-in-fact for Mona G. Estey</signatureName>
        <signatureDate>2010-12-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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