UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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 22, 2014

RIVERBED TECHNOLOGY, INC.

(Exact name of registrant as specified in its charter)

680 Folsom Street

San Francisco, CA 94107

(Address of principal executive offices, including zip code)

(415) 247-8800

(Registrant’s telephone number, including area code)

(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 (see General Instruction A.2. below):

Approval of the 2014 Equity Incentive Plan

At the 2014 Annual Meeting of Stockholders of Riverbed Technology, Inc. (“Riverbed”) held on May 22, 2014 (the “Annual Meeting”), the stockholders of Riverbed approved Riverbed’s 2014 Equity Incentive Plan (the “2014 Plan”). The terms and conditions of the 2014 Plan are described in Riverbed’s Proxy Statement dated April 9, 2014.

A copy of the 2014 Plan is attached as Exhibit 10.1 and incorporated by reference herein.

At the Annual Meeting, the stockholders voted on the following matters:

Proposal One – Director Election. At the Annual Meeting, Mark Lewis did not receive a majority of votes cast in favor of his re-election to the Board of Directors (the “Board”). The table below presents the voting results of the election. In accordance with Riverbed’s Corporate Governance Guidelines, Mr. Lewis has offered his resignation from the Board, which the Board intends to consider carefully.

Proposal Two – Ratification of the Appointment of Independent Registered Public Accounting Firm. The appointment of Ernst & Young LLP as Riverbed’s independent registered public accounting firm for the fiscal year ending December 31, 2014 was ratified.

Proposal Three – Advisory Vote on Executive Compensation. The stockholders did not approve, on a non-binding advisory basis, the compensation of Riverbed’s named executive officers.

Proposal Four – Approval of the 2014 Equity Incentive Plan. The 2014 Plan was approved.

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 hereunto duly authorized.

EXHIBIT INDEX