As filed with the Securities and Exchange Commission on August 18, 2004

Registration No. 333-

SECURITIES AND EXCHANGE COMMISSION

FORM S-8

REGISTRATION STATEMENT
UNDER THE
SECURITIES ACT OF 1933

GSI LUMONICS INC.

39 Manning Road
Billerica, MA 01821
(978) 439-5511

(Address of Principal Executive Offices, Including Zip Code)

SECOND RESTATEMENT OF
GSI LUMONICS INC.
1995 EQUITY INCENTIVE PLAN
(Full Title of the Plan)

Charles D. Winston
39 Manning Road
Billerica, MA 01821
(978) 439-5511

(Name, Address and Telephone Number, Including Area Code, of Agent For Service)

CALCULATION OF REGISTRATION FEE

(1) Estimated pursuant to Rule 457(h) and (c) solely for the purpose of calculating the amount of registration fee based on the average high and low prices reported by Nasdaq on August 13, 2004.

This Registration Statement registers additional securities of the same class as other securities for which a Registration Statement on Form S-8 (No. 333-43080) relating to the registrant’s 1995 Equity Incentive Plan is effective. Pursuant to General Instruction E of Form S-8, the contents of the above-listed Registration Statement are hereby incorporated by reference.

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Table of Contents

Part II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference

     The following documents are incorporated in this registration statement by reference:

     In addition, all documents subsequently filed by the registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the filing of a post-effective amendment which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference herein and to be a part hereof from the date of the filing of such documents.

Item 8. Exhibits

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SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Billerica, Massachusetts, on August 18, 2004.

POWER OF ATTORNEY

     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below constitutes and appoints Charles D. Winston and Thomas R. Swain, and each of them, his true and lawful attorneys-in-fact and agents, each with full power of substitution and resubstitution, for him and in his name, place and stead, in any and all capacities, to sign any or all amendments (including post-effective amendments) to this registration statement and to file the same, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them, or their substitute or substitutes, may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, this registration statement has been signed by the following persons in the capacities and on the date indicated.

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Exhibit Index