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): March 1, 2013

MULTI-FINELINE ELECTRONIX, INC.

(Exact name of registrant as specified in its charter)

8659 Research Dr.

Irvine, CA 92618

(Address of Principal Executive Offices) (Zip Code)

(949) 453-6800

(Registrant’s telephone number, including area code)

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:

On March 1, 2013, MFLEX Chengdu Co., Ltd. (“MCH”), a subsidiary of Multi-Fineline Electronix, Inc. (the “Company”), entered into a Line of Credit Agreement (the “MCH Credit Line”) with Bank of China Co., Ltd. Chengdu Development West Zone Sub-Branch (“BC”), providing for a line of credit to MCH in an amount of $11 million US dollars. The MCH Credit Line will mature on February 5, 2014. MCH and BC have also entered into a Facility Offer Letter dated as of March 1, 2013 (the “Facility Offer Letter”). The Facility Offer Letter sets forth the MFLEX pricing negotiated by BC and MCH (the “MFLEX Price”). The loan interest rate shall be negotiated by the parties based on the lending cost in the Chinese market for US dollars on the day the loan is made. The MCH Credit Line will be used for working capital and general business purposes. A copy of each of the MCH Credit Line and the Facility Offer Letter are attached hereto.

(b) On March 7, 2013, Mr. Kheng-Joo Khaw, a Class I director, notified Multi-Fineline Electronix, Inc. (the “Company”) of his resignation from the Board of Directors of the Company. There were no disagreements with the Company that led to Mr. Khaw’s decision to resign.

The Company held its Annual Meeting of Stockholders on March 6, 2013. The stockholders considered three proposals, each of which is described in more detail in the Company’s definitive proxy statement dated January 17, 2013.

Proposal 1: Election of Directors:

All of the foregoing candidates were elected and each received affirmative votes not only from more than a majority of the shares voting, but also from a majority of the outstanding shares.

Proposal 2: Ratification of Appointment of Independent Registered Public Accounting Firm:

The foregoing proposal was approved.

Proposal 3: Non-Binding Advisory Vote to Approve the Compensation of the Company’s Named Executive Officer Compensation Practices

The foregoing proposal was approved.

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.

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