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 11, 2013

POTOMAC ELECTRIC POWER COMPANY

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code (202) 872-2000

Not Applicable

(Former name or former address, if changed since last report.)

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:

Potomac Electric Power Company (the Company) has entered into a Purchase Agreement, dated March 11, 2013 (the Purchase Agreement), with Barclays Capital Inc., Credit Suisse Securities (USA) LLC, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Scotia Capital (USA) Inc., as representatives of the several underwriters named therein (collectively, the Underwriters), for the offer and sale of $250,000,000 in aggregate principal amount of the Company’s First Mortgage Bonds, 4.15% Series due March 15, 2043 (the Bonds) in an underwritten offering registered on a Registration Statement on Form S-3 (Registration No. 333-169477-03), which was filed with the Securities and Exchange Commission on September 20, 2010 (the Offering). The Purchase Agreement is filed herewith as Exhibit 1.1 and the form of Bond is filed herewith as Exhibit 4.1. The Bonds are initially being offered to the public at a price of 99.609% of the principal amount. At the closing of the Offering, which is scheduled to occur on March 18, 2013, the Company will realize, after deduction of the underwriting discount of 0.875% of the principal amount and before deduction of Offering expenses, net proceeds of approximately $246.8 million.

The Bonds will be issued under the Mortgage and Deed of Trust, dated July 1, 1936, between the Company and The Bank of New York Mellon, as successor trustee (the Mortgage Trustee), as amended and supplemented from time to time, including pursuant to the Supplemental Indenture, dated as of March 11, 2013 (the Supplemental Indenture), relating to the issuance of the Bonds (the Mortgage). Subject to the exceptions and limitations contained in the Mortgage, the Bonds will be secured, together with all bonds now or hereafter issued, under the Mortgage, by a first lien (subject to certain leases, permitted liens and other minor matters) on substantially all of the Company’s real and personal property and franchises. A copy of the Supplemental Indenture is filed herewith as Exhibit 4.2.

The Company may redeem all or any portion of the Bonds at its option, at any time prior to their maturity, at the redemption price described below. The Company will give notice of its intent to redeem the Bonds at least 30 days, but no more than 60 days, prior to the redemption date. If the Company redeems all or any part of the Bonds as described above prior to September 15, 2042, the Company will pay a redemption price equal to the greater of (i) 100% of the principal amount of the Bonds being redeemed; and (ii) a make-whole amount as set forth in the Supplemental Indenture, plus, in each case, accrued and unpaid interest on such Bonds to the redemption date. If the Company redeems all or any part of the Bonds pursuant to the provisions thereof on or after September 15, 2042, the Company will pay a redemption price equal to 100% of the principal amount of the Bonds being redeemed plus accrued and unpaid interest thereon.

The Company intends to use the net proceeds from the Offering to repay outstanding commercial paper of the Company and the remainder thereof, if any, for general corporate purposes.

The legality opinion of Kevin C. Fitzgerald, Esq., Executive Vice President and General Counsel of the Company, relating to the issuance of the Bonds, is filed herewith as Exhibit 5.1.

In the ordinary course of business, the Underwriters and their respective affiliates have from time to time performed and may in the future perform various financial advisory, commercial banking and investment banking services for the Company and its affiliates, for which they received, or will continue to receive, customary fees or compensation. In addition, affiliates of certain of the Underwriters are paying agents under the Company’s commercial paper programs and lenders under the Company’s primary credit facility, and from time to time perform treasury services for the Company.

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The following exhibits are filed herewith:

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SIGNATURES

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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EXHIBIT INDEX

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