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 Act of 1934

Date of Report (Date of earliest event reported): June 18, 2012

Synthesis Energy Systems, Inc.

(Exact name of registrant as specified in its charter)

(713) 579-0600

(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 (see General Instruction A.2. below):

On June 18, 2012, Synthesis Energy Systems, Inc. (the “Company”) entered into a Share Purchase Agreement (the “Hongye Agreement”) with Hongye International Investment Group Co., Ltd. (“Hongye”), pursuant to which Hongye will acquire 6,175,093 shares (the “Hongye Shares”) of the Company’s common stock, par value $.01 per share (the “Common Stock”), for $1.50 per share, for an aggregate purchase price of $9,262,639, and entered into a Share Purchase Agreement (the “Zhongmo Agreement”) with Shanghai Zhongmo Investment Management Co., Ltd. (“Zhongmo”), pursuant to which Zhongmo will acquire 4,177,335 shares (the “Zhongmo Shares,” and together with the Hongye Shares, the “Shares”) of the Common Stock for $1.50 per share, for an aggregate purchase price of $6,266,002. The terms and conditions of the Hongye Agreement and the Zhongmo Agreement are summarized below. Copies of the Hongye Agreement and the Zhongmo Agreement are filed herewith as Exhibits 10.1 and 10.2, respectively.

The consummation of the transactions contemplated by the Hongye Agreement and the Zhongmo Agreement are each subject to the following conditions precedent: (i) the representations and warranties of all parties shall be true and correct as of the closing date in all material respects as though made at such date (except to the extent that a representation and warranty speaks as of an earlier date, in which case such representation and warranty shall be true as of such earlier date); and (ii) Hongye and Zhongmo, as applicable, shall have engaged a qualified institutional investor (a “QDII”) in China to facilitate their respective purchases. Hongye and Zhongmo have determined that investing through a QDII is the optimal method to complete their investment. Under the QDII scheme in China, qualified securities firms can raise money from Chinese investors through asset management plans approved by the China Securities Regulatory Commission, and apply those funds to an investment in an overseas securities market.

The Hongye Agreement and the Zhongmo Agreement include several post-closing covenants and agreements:

In addition, under the Hongye Agreement, the Company has agreed to certain additional post-closing covenants and agreements:

Both the Hongye Agreement and the Zhongmo Agreement may be terminated upon the occurrence of any of the following: (i) by any party if any governmental authority shall have issued an order, decree or ruling enjoining or otherwise prohibiting the transactions contemplated by such agreement; (ii) by any party, if there shall have been a breach of any other party’s covenants, agreements, representations or warranties set forth in such agreement which breach, either individually or in the aggregate, would result in the failure of any condition precedent set forth above; (iii) by any party, if the closing date does not occur by July 31, 2012, provided that such date can be extended by mutual agreement in writing of the parties; or (iv) at any time upon the mutual agreement of the parties. In connection with the execution of the agreement, Hongye will deposit the Renminbi equivalent of US$1,000,000 with the Company. In the event that (a) Hongye terminates the agreement pursuant to (ii) above, (b) Hongye and/or the Company terminate the agreement pursuant to (i) or (iv) above, or (c) closing takes place in accordance with the terms of the agreement, the deposit shall be returned in full to Hongye by the Company. In the event that the agreement is terminated by either Hongye or the Company for any other reason, the Company shall be entitled to retain the deposit.

The text set forth in Item 1.01 regarding the sale of the Shares to Hongye and Zhongmo under the Hongye Agreement and the Zhongmo Agreement is incorporated into this section by reference.

In accordance with General Instruction B.2. of Form 8-K, the information presented under this Item 7.01 shall not be deemed “filed” for purposes of Section 18 of the Exchange Act, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

On June 18, 2012, the Company issued a press release announcing the execution of the Purchase Agreement. A copy of the press release is furnished herewith as Exhibit 99.1.

Exhibits

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 thereunto duly authorized.

Exhibit Index