Blue Buffalo Pet Products Inc. has filed a registration statement on Form S-1 with the Securities and Exchange Commission (SEC) relating to the proposed secondary offering of 25,000,000 shares of its common stock by certain selling stockholders named in the registration statement. The underwriters will have a 30-day option from the date of the offering to purchase up to an additional 3,750,000 shares of common stock from the selling stockholders.

Blue Buffalo is not offering any shares of common stock in the proposed offering and will not receive any proceeds from the sale of shares in the proposed offering.

J.P. Morgan Securities LLC and Citigroup Global Markets Inc. are acting as joint book-running managers for the proposed offering.

A registration statement on Form S-1 relating to the proposed offering has been filed with the SEC but has not yet become effective. The shares to be registered may not be sold nor may offers to buy be accepted prior to the time the registration statement becomes effective.

The offering is being made only by means of a prospectus. A copy of the prospectus related to the offering may be obtained by contacting J.P. Morgan Securities LLC, c/oBroadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, or by telephone at +1.866.803.9204; or Citigroup Global Markets Inc., c/o Broadridge Financial Services, 1155 Long Island Avenue, Edgewood, NY, 11717, or by telephone at +1.800.831.9146.