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 7, 2012

CENTERPOINT ENERGY HOUSTON ELECTRIC, LLC

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (713) 207-1111

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 August 7, 2012, CenterPoint Energy Houston Electric, LLC (the “Company”) entered into two Underwriting Agreements (the “Underwriting Agreements”), among the Company and the several Underwriters named in Schedule I to each Underwriting Agreement, relating to the underwritten public offering of $300,000,000 aggregate principal amount of the Company’s 2.25% General Mortgage Bonds, Series V, due 2022, and $500,000,000 aggregate principal amount of the Company’s 3.55% General Mortgage Bonds, Series W, due 2042 (collectively, the “Bonds”). The offering is being made pursuant to the Company’s registration statement on Form S-3 (Registration No. 333-169666-02), which became effective upon filing with the Securities and Exchange Commission.

The Bonds are expected to be issued on August 10, 2012 pursuant to a General Mortgage Indenture, dated as of October 10, 2002, as supplemented and amended, between the Company and The Bank of New York Mellon Trust Company, National Association (successor in trust to JPMorgan Chase Bank), as trustee (the “Trustee”), as supplemented by the Twenty-Second Supplemental Indenture thereto, to be dated as of August 10, 2012, between the Company and the Trustee. The form, terms and provisions of the Bonds are further described in the officer’s certificate of the Company to be dated August 10, 2012 (the “Officer’s Certificate”) and the prospectus supplement of the Company dated August 7, 2012, together with the related prospectus dated September 30, 2010, as filed with the Securities and Exchange Commission under Rule 424(b) of the Securities Act of 1933, as amended, on August 8, 2012, which description is incorporated herein by reference.

A copy of the Underwriting Agreements, the General Mortgage Indenture, the form of the Twenty-Second Supplemental Indenture and the form of Officer’s Certificate have been filed as Exhibits 1.1, 1.2, 4.1, 4.4 and 4.5, respectively, to this report and are incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits

The exhibits listed below are filed herewith.

Agreements and forms of agreements included as exhibits are included only to provide information to investors regarding their terms. Agreements and forms of agreements listed below may contain representations, warranties and other provisions that were made, among other things, to provide the parties thereto with specified rights and obligations and to allocate risk among them, and no such agreement or form of agreement should be relied upon as constituting or providing any factual disclosures about the Company, any other persons, any state of affairs or other matters.

(d) 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.

EXHIBIT INDEX