UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

Date of report (Date of earliest event reported): August 30, 2011

Codexis, Inc.

(Exact name of Registrant as Specified in its Charter)

200 Penobscot Drive

Redwood City, CA 94063

(Address of Principal Executive Offices) (Zip Code)

(650) 421-8100

(Registrant’s telephone number, including area code)

Not Applicable

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

On August 30, 2011, Codexis, Inc. (the “Company”) entered into an amendment (the “Grant Amendment”) to the grant (the “Grant”) awarded by the Economic Development Board of Singapore (the “EDB”). The Grant partially supports activities in our Singapore facility, which until recently has focused on pharmaceutical research and development. The Grant Amendment, among other things, permits the scope of the research activities that qualify for reimbursement under the Grant to include chemical and water industry projects, extends the term of the Grant by one (1) year, to March 31, 2013, and confirms the list of expenses that qualify for reimbursement under the Grant.

The foregoing is only a summary of the material terms of the Grant Amendment, does not purport to be a complete description of the rights and obligations of the parties thereunder and is qualified in its entirety by reference to the Grant Amendment that will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the fiscal quarter ending September 30, 2011.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: September 6, 2011