UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 1 to

FORM 20-F

     ¨ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

     x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2011

OR

     ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

     ¨ SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of event requiring this shell company report: N/A

For the transition period from                      to                     

Commission file number: 000-51380

Silicon Motion Technology Corporation

(Exact name of Registrant as specified in its charter)

Cayman Islands

(Jurisdiction of incorporation or organization)

8F-1, No. 36, Taiyuan St.,

Jhubei City, Hsinchu County 302

Taiwan

Tel: +886 3 552 6888

Fax: + 886 3 560 0336

(Address of principal executive offices)

Securities registered or to be registered pursuant to Section 12(b) of the Act:

Title of each class	Name of each exchange on which registered
Ordinary shares, par value US$0.01 per share* American Depositary Shares, each representing four ordinary shares	Nasdaq Global Select Market

* Not for trading, but only in connection with the listing on the Nasdaq Global Select Market of American Depositary Shares, or ADSs, each representing four ordinary shares.

Securities registered or to be registered pursuant to Section 12(g) of the Act:

None

Securities registered or to be registered pursuant to Section 15(d) of the Act:

None

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report: 124,572,544, ordinary shares as of December 31, 2011, US$0.01 par value per share.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.  Yes ¨   No x

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.   Yes ¨  No x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Sections 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 whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).  Yes x  No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filed. See definition of “accelerated filer and large accelerated filer” in Rule 12b-2 of the Exchange Act. (Check one):

Large accelerated filer  ¨                 Accelerated filer  x                 Non-accelerated filer  ¨

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

U.S. GAAP  x International Financial Reporting Standards as issued by the International Accounting Standards Board  ¨ Other  ¨

If “Other” has been checked in response to the previous question, indicate by check mark which financial statement item the registrant has elected to follow.  ¨ Item 17  ¨ Item 18

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act):  Yes ¨  No x

EXPLANATORY NOTE

This Amendment No. 1 to Form 20-F for the fiscal year ended December 31, 2011, which was originally filed with the Securities and Exchange Commission on April 30, 2012 (the “2011 Form 20-F”), is being filed solely for purposes of furnishing Interactive Data File disclosure as Exhibit 101 in accordance with Rule 405 of Regulation S-T. In accordance with the applicable grace period, the Interactive Data File disclosure in Exhibit 101 is being furnished less than 30 days after the original filing of the 2011 Form 20-F.

Other than as expressly set forth above, this Amendment No. 1 to Form 20-F does not, and does not purport to, amend, update or restate the information in any other item of the 2011 Form 20-F, or reflect any events that have occurred after the 2011 Form 20-F was originally filed.

ITEM 19. EXHIBITS

Exhibit Number	Description
101.INS*	XBRL Instance Document
101.SCH*	XBRL Taxonomy Extension Schema Document
101.CAL*	XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF*	XBRL Taxonomy Extension Definition Linkbase Document
101.LAB*	XBRL Taxonomy Extension Label Linkbase Document
101.PRE*	XBRL Taxonomy Extension Presentation Linkbase Document

* XBRL (eXtensible Business Reporting Language) information is furnished and not filed or a part of a registration statement or prospectus for purposes of Sections 11 or 12 of the Securities Act of 1933, as amended, is deemed not filed for purposes of Section 18 of the Exchange Act of 1934, as amended, and otherwise is not subject to liability under these sections.

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SIGNATURES

The registrant hereby certifies that it meets all the requirements for filing on Form 20-F and that it has duly caused and authorized the undersigned to sign this annual report on its behalf.

SILICON MOTION TECHNOLOGY CORPORATION
By:	/S/    WALLACE C. KOU
	Wallace C. Kou, President & Chief Executive Officer

Date: May 15, 2012

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