-----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,
 PuiO5Td415NTj8cai63yo8jOfqYYK/3GyMZYbpmxFMNC6j/hC5zOs6kvWETXrWaU
 9eGa+qGUOBm945bdssX+Rw==

<SEC-DOCUMENT>0001127602-10-021489.txt : 20100817
<SEC-HEADER>0001127602-10-021489.hdr.sgml : 20100817
<ACCEPTANCE-DATETIME>20100817163129
ACCESSION NUMBER:		0001127602-10-021489
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100813
FILED AS OF DATE:		20100817
DATE AS OF CHANGE:		20100817

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Vahaviolos Sotirios J.
		CENTRAL INDEX KEY:			0001473727

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34481
		FILM NUMBER:		101023457

	MAIL ADDRESS:	
		STREET 1:		C/O MISTRAS GROUP, INC.
		STREET 2:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Mistras Group, Inc.
		CENTRAL INDEX KEY:			0001436126
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
		IRS NUMBER:				223341267
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0531

	BUSINESS ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
		BUSINESS PHONE:		609-716-4000

	MAIL ADDRESS:	
		STREET 1:		195 CLARKSVILLE ROAD
		CITY:			PRINCETON JUNCTION
		STATE:			NJ
		ZIP:			08550
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-08-13</periodOfReport>

    <issuer>
        <issuerCik>0001436126</issuerCik>
        <issuerName>Mistras Group, Inc.</issuerName>
        <issuerTradingSymbol>MG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001473727</rptOwnerCik>
            <rptOwnerName>Vahaviolos Sotirios J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MISTRAS GROUP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>195 CLARKSVILLE ROAD</rptOwnerStreet2>
            <rptOwnerCity>PRINCETON JUNCTION</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08550</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <officerTitle>Chairman, President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9900</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.8944</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11346663</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15100</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.7628</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11361763</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price represents the weighted average purchase price for the transactions reported on this line.  The range of the prices for the transactions reported on this line were $9.76 to $9.98.  Upon request by the Commmission staff or a security holder of the issuer, the full information regarding the number of shares purchased at each separate price shall be provided.  This information has been provided to the issuer.</footnote>
        <footnote id="F2">The price represents the weighted average purchase price for the transactions reported on this line.  The range of the prices for the transactions reported on this line were $9.43 to $9.92.  Upon request by the Commmission staff or a security holder of the issuer, the full information regarding the number of shares purchased at each separate price shall be provided.  This information has been provided to the issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Michael C. Keefe, attorney-in-fact for Sotirios J. Vahaviolos</signatureName>
        <signatureDate>2010-08-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----