    <SEC-DOCUMENT>0001564590-15-002540-index.html : 20150413
    <SEC-HEADER>0001564590-15-002540.hdr.sgml : 20150413
    <ACCEPTANCE-DATETIME>20150413155956
    ACCESSION NUMBER:		0001564590-15-002540
    CONFORMED SUBMISSION TYPE:	DEF 14A
    PUBLIC DOCUMENT COUNT:		11
    CONFORMED PERIOD OF REPORT:	20150512
    FILED AS OF DATE:		20150413
    DATE AS OF CHANGE:		20150413
    EFFECTIVENESS DATE:		20150413

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			GSI GROUP INC
    		CENTRAL INDEX KEY:			0001076930
    		STANDARD INDUSTRIAL CLASSIFICATION:	MISCELLANEOUS ELECTRICAL MACHINERY, EQUIPMENT & SUPPLIES [3690]
    		IRS NUMBER:				980110412
    		STATE OF INCORPORATION:			A3
    		FISCAL YEAR END:			1231

    	FILING VALUES:
    		FORM TYPE:		DEF 14A
    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	001-35083
    		FILM NUMBER:		15766762

    	BUSINESS ADDRESS:
    		STREET 1:		125 MIDDLESEX TURNPIKE
    		STREET 2:		.
    		CITY:			BEDFORD
    		STATE:			MA
    		ZIP:			01730
    		BUSINESS PHONE:		781-266-5618

    	MAIL ADDRESS:
    		STREET 1:		125 MIDDLESEX TURNPIKE
    		STREET 2:		.
    		CITY:			BEDFORD
    		STATE:			MA
    		ZIP:			01730

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	GSI LUMONICS INC
    		DATE OF NAME CHANGE:	19990401

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	GSI LUMONICS
    		DATE OF NAME CHANGE:	19990331

    	FORMER COMPANY:
    		FORMER CONFORMED NAME:	LUMONICS INC
    		DATE OF NAME CHANGE:	19990115
    </SEC-HEADER>
    <DOCUMENT>
    <TYPE>DEF 14A
    <SEQUENCE>1
    <FILENAME>gsig-def14a20150415.htm
    <DESCRIPTION>DEF 14A
    <TEXT>
    Document 1 - file: gsig-def14a20150415.htm

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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 2 - file: g201504131721024773600.jpg

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    <DESCRIPTION>GRAPHIC
    <TEXT>
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    Document 4 - file: g201504131721026963602.jpg

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    Document 5 - file: g201504131721027903603.jpg

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    Document 7 - file: g201504131721098523605.jpg

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    Document 8 - file: g201504131721206493606.jpg

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    <DESCRIPTION>GRAPHIC
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    Document 9 - file: g201504131721214933607.jpg

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    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 10 - file: g201504131721220403608.jpg

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    <DOCUMENT>
    <TYPE>GRAPHIC
    <SEQUENCE>11
    <FILENAME>g201504131721229463609.jpg
    <DESCRIPTION>GRAPHIC
    <TEXT>
    Document 11 - file: g201504131721229463609.jpg

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