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): May 15, 2012

PETROLEUM DEVELOPMENT CORPORATION

(Doing Business as PDC Energy)

(Exact name of registrant as specified in its charter)

1775 Sherman Street, Suite 3000

Denver, Colorado 80203

Registrant’s telephone number, including area code: (303) 860-5800

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):

Item 1.01. Entry into a Material Definitive Agreement.

On May 15, 2012, Petroleum Development Corporation (dba PDC Energy) (the “Company”), in connection with a registered underwritten public offering of shares of its common stock (the “Offering”), entered into an underwriting agreement (the “Underwriting Agreement”) with Merrill Lynch, Pierce, Fenner & Smith Incorporated, J.P. Morgan Securities LLC and Wells Fargo Securities, LLC, as representatives of the underwriters (the “Underwriters”) named therein, pursuant to which the Company agreed to sell 6,500,000 shares of its common stock through the Underwriters at a public offering price of $26.50 per share. In addition, pursuant to the Underwriting Agreement, the Underwriters have been granted an option, exercisable within 30 days, to purchase up to an additional 975,000 shares of common stock on the same terms and conditions. The Underwriting Agreement contains customary representations, warranties and agreements by the Company and customary conditions to closing, obligations of the parties and termination provisions. Additionally, the Company has agreed to indemnify the Underwriters against certain liabilities, including liabilities under the Securities Act of 1933, or to contribute to payments the Underwriters may be required to make due to any such liabilities.

A copy of the Underwriting Agreement is attached as Exhibit 1.1 hereto and is incorporated by reference into this Item 1.01. The above description is qualified in its entirety by reference to such exhibit.

A copy of the Underwriting Agreement has been included to provide security holders with information regarding its terms. It is not intended to provide any other factual information about the Company. The representations, warranties and covenants contained in the Underwriting Agreement were made solely for purposes of the Offering and as of specific dates, were solely for the benefit of the parties to the Underwriting Agreement, may be subject to limitations agreed upon by the contracting parties, including being qualified by confidential disclosures made for the purposes of allocating contractual risk between the parties to the Underwriting Agreement instead of establishing these matters as facts, and may be subject to standards of materiality applicable to the contracting parties that differ from those applicable to security holders. Security holders are not third-party beneficiaries under the Underwriting Agreement and should not rely on the representations, warranties and covenants or any descriptions thereof as characterizations of the actual state of facts or condition of the Company. Moreover, information concerning the subject matter of the representations and warranties may change after the date of the Underwriting Agreement, which subsequent information may or may not be fully reflected in the Company’s public disclosures.

Certain of the Underwriters or their affiliates have from time to time provided investment banking, commercial banking and financial advisory services to the Company, for which they have received customary compensation. The Underwriters and their affiliates may provide similar services in the future. In particular, certain of the Underwriters or their affiliates are lenders under the Company’s revolving credit facility and will receive a portion of the proceeds from the Offering, as described in the prospectus supplement relating to the Offering. In addition, from time to time, certain of the Underwriters and their affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in the Company’s debt or equity securities or loans, and may do so in the future.

Item 9.01. Financial Statements and 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 hereunto duly authorized.

Date: May 16, 2012

EXHIBIT INDEX