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): June 5, 2012

COMSTOCK RESOURCES, INC.

(Exact Name of Registrant as Specified in Charter)

5300 Town and Country Boulevard

Suite 500

Frisco, Texas 75034

(Address of principal executive offices)

(972) 668-8800

(Registrant’s Telephone No.)

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:

Item 1.01 Entry into a Material Definitive Agreement

On June 5, 2012, Comstock Resources, Inc. (the “Company”) completed the public offering of $300.0 million aggregate principal amount of 9 ¹/2% Senior Notes due 2020 (the “Notes”), which are fully and unconditionally guaranteed by the Company’s principal subsidiaries (“Subsidiary Guarantors”) Comstock Oil & Gas, LP, Comstock Oil & Gas-Louisiana, LLC, Comstock Oil & Gas GP, LLC, Comstock Oil & Gas Investments, LLC and Comstock Oil & Gas Holdings, Inc.

The terms of the Notes are governed by the Indenture dated as of October 9, 2009 (the “Base Indenture”), among the Company, the Subsidiary Guarantors and The Bank of New York Mellon Trust Company, N.A., as trustee (the “Trustee”), as amended and supplemented by the Fourth Supplemental Indenture dated as of June 5, 2012 (the “Fourth Supplemental Indenture”) (the Base Indenture, as amended and supplemented by the Fourth Supplemental Indenture (the “Indenture”)).

The Notes will mature on June 15, 2020, and interest is payable on the Notes on each June 15 and December 15, commencing December 15, 2012. The record date is June 1 and December 1. The Company may redeem some or all of the Notes at any time on or after June 15, 2016 at the redemption prices specified in the Indenture. The Company may also redeem up to 35% of the Notes using the net proceeds of certain equity offerings completed before June 15, 2015 at a redemption price as specified in the Indenture. If the Company sells certain assets or experiences a change of control, as described in the Indenture, each holder of the Notes will have the right to require the Company to repurchase the Notes at a purchase price described in the Indenture plus accrued and unpaid interest, if any, to the date of such repurchase.

The Notes are the Company’s senior unsecured obligations. The Notes will rank equally in right of payment with all of the Company’s existing and future senior indebtedness and senior in right of payment to all of the Company’s future subordinated indebtedness. The Notes will be effectively subordinated to all of the Company’s existing and future secured indebtedness to the extent of the collateral securing such indebtedness, including under the Company’s bank credit facility.

The Indenture restricts the Company’s ability and the ability of certain of its subsidiaries to, among other things: (i) incur additional indebtedness; (ii) pay distributions or dividends on equity or purchase, redeem or otherwise acquire equity; (iii) make certain investments; (iv) use assets as collateral in other transactions; (v) sell certain assets or merge with or into other companies; and (vi) enter into transactions with affiliates. These covenants are subject to a number of important exceptions and qualifications.

The Indenture contains customary events of default, including:

If an event of default under the Indenture occurs and is continuing, the Trustee or the holders of at least 25% in principal amount of the outstanding Notes may declare the principal of, premium, if any, and accrued and unpaid interest, if any, on the Notes to be due and payable, or, in the case of certain events of default relating to bankruptcy, insolvency or reorganization, those amounts will automatically become immediately due and payable.

Other material terms of the Notes, the Base Indenture and the Third Supplemental Indenture are described in the Prospectus Supplement, dated May 31, 2012, as filed by the Company and the Subsidiary Guarantors with the Securities and Exchange Commission (the “Commission”). The foregoing descriptions of the Base Indenture, the Fourth Supplemental Indenture and the Notes are qualified in their entirety by reference to such Base Indenture and the Fourth Supplemental Indenture (including the form of Notes attached thereto), which is filed herewith as Exhibit 4.1 and incorporated herein by reference.

The Company and the Subsidiary Guarantors registered the sale of the 2020 Notes and the underlying guarantees with the Commission pursuant to an automatic shelf Registration Statement on Form S-3 (Registration No. 333-162328) filed on October 5, 2009 (the “Registration Statement”). The Company used the net proceeds from the offering of approximately $278.9 million to repay outstanding borrowings under its bank credit facility.

As previously reported, on May 31, 2012, the Company entered into an underwriting agreement with Merrill Lynch, Pierce, Fenner & Smith Incorporated, as representative of the underwriters named therein, in connection with an underwritten public offering of the Notes.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

The description contained under Item 1.01 above is incorporated by reference in its entirety into this Item 2.03.

Item 9.01 Financial Statements and Exhibits

(d) Exhibits

SIGNATURES

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

Exhibits Index