UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

x Annual Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the fiscal year ended May 31, 2005

or

¨ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

For the transition period from              to             

Commission File No. 1-15461

MATRIX SERVICE COMPANY

(Exact name of registrant as specified in its charter)

Delaware	73-1352174
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
10701 East Ute Street Tulsa, Oklahoma	74116
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s telephone number, including area code: (918) 838-8822

Securities Registered Pursuant to Section 12(b) of the Act: None

Securities Registered Pursuant to Section 12(g) of the Act:

Common Stock, par value $0.01 per share

Preferred Share Purchase Rights

(Title of class)

Name of Each Exchange On Which Registered: NASDAQ National Market (Common Stock)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports) and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  ¨

Indicate by check mark whether the registrant is an accelerated filer (as defined in Rule 12 b-2 of the Act).    Yes  x    No  ¨

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

The aggregate market value of the registrant’s common stock held by non-affiliates computed by reference to the price at which the common stock was last sold as of the last business day of the registrant’s most recently completed second quarter was approximately $109,259,750.

The number of shares of the registrant’s common stock outstanding as of August 12, 2005 was 17,413,526 shares.

Documents Incorporated by Reference

Certain sections of the registrant’s definitive proxy statement relating to the registrant’s 2005 annual meeting of stockholders, which definitive proxy statement will be filed within 120 days of the end of the registrant’s fiscal year, are incorporated by reference into Part III of this Form 10-K.

EXPLANATORY NOTE

Matrix Service Company (the “Company”) is filing this Amendment No. 1 on Form 10-K/A to amend its Annual Report on Form 10-K for the fiscal year ended May 31, 2005 (the “Original 10-K”), originally filed on August 17, 2005, solely for the purpose of correcting the cover page of the Original 10-K, in which the Company inadvertently checked the box “no,” to the questions (1) whether the Company has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months and (2) has been subject to such filing requirements for the past 90 days.

1

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, Matrix Service has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	MATRIX SERVICE
Date: October 20, 2005
	Michael J. Hall, President