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): April 23, 2014

BioMed Realty Trust, Inc.

BioMed Realty, L.P.

(Exact name of registrant as specified in its charter)

17190 Bernardo Center Drive

San Diego, California 92128

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code: (858) 485-9840

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 April 23, 2014, BioMed Realty, L.P. (the “Operating Partnership”), the operating partnership subsidiary of BioMed Realty Trust, Inc. (the “Company”), issued $400.0 million aggregate principal amount of its 2.625% Senior Notes due 2019 (the “Notes”).

The terms of the Notes are governed by a base indenture, dated March 30, 2011, by and among the Operating Partnership, as issuer, the Company, as guarantor, and U.S. Bank National Association, as trustee (the “Trustee”), as supplemented by a supplemental indenture, dated as of April 23, 2014, by and among the Operating Partnership, the Company and the Trustee (the base indenture and the supplemental indenture, collectively the “Indenture”). The Indenture contains various restrictive covenants, including limitations on the Operating Partnership’s ability to incur additional indebtedness, requirements to maintain a pool of unencumbered assets and requirements to maintain insurance with financially sound and reputable insurance companies. Copies of the base indenture and supplemental indenture, including the form of the Notes and guarantee of the Notes by the Company, the terms of which are incorporated herein by reference, are attached as Exhibits 4.1 and 4.2, respectively, to this Current Report on Form 8-K. See Item 2.03 below for more information.

The net proceeds from the issuance of the Notes will be approximately $394.5 million, after deducting the underwriters’ discounts and the Operating Partnership’s estimated offering expenses.

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

On April 23, 2014, the Operating Partnership issued $400.0 million aggregate principal amount of Notes. The Operating Partnership offered the Notes at 99.408% of the principal amount thereof. The Notes are general unsecured senior obligations of the Operating Partnership and rank equally in right of payment with all other senior unsecured indebtedness of the Operating Partnership. However, the Notes are effectively subordinated to the Operating Partnership’s existing and future mortgages and other secured indebtedness (to the extent of the value of the collateral securing such indebtedness) and to all existing and future preferred equity and liabilities, whether secured or unsecured, of the Operating Partnership’s subsidiaries, including guarantees provided by the Operating Partnership’s subsidiaries under the credit agreement governing the Operating Partnership’s $900.0 million unsecured line of credit and $350.0 million unsecured senior term loan due 2018. The Notes bear interest at 2.625% per annum. Interest is payable on May 1 and November 1 of each year beginning November 1, 2014 until the maturity date of May 1, 2019. The Operating Partnership’s obligations under the Notes are fully and unconditionally guaranteed by the Company. Copies of the base indenture and supplemental indenture, including the form of the Notes and guarantee of the Notes by the Company, the terms of which are incorporated herein by reference, are attached as Exhibits 4.1 and 4.2, respectively, to this Current Report on Form 8-K.

The Notes will be redeemable in whole at any time or in part from time to time, at the Operating Partnership’s option and in its sole discretion, at a redemption price equal to the greater of:

plus, in each case, accrued and unpaid interest thereon to the redemption date.

Notwithstanding the foregoing, if the Notes are redeemed on or after 30 days prior to the maturity date, the redemption price will be equal to 100% of the principal amount of the Notes being redeemed, plus accrued and unpaid interest thereon to the redemption date.

Certain events are considered events of default, which may result in the accelerated maturity of the Notes, including:

Item 9.01 Financial Statements and Exhibits.

(d) The following exhibits are filed herewith:

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.