W.W. Grainger (GWW)

(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:

On August 20, 2007, in connection with the restored repurchase authority referred to in Item 7.01 below, the Registrant entered into an accelerated share repurchase agreement to purchase approximately $500 million of its outstanding common stock from Goldman Sachs & Co. (“GSC”). The exact purchase price per share and number of shares to be delivered by GSC will be fixed in accordance with the agreement, which is expected to have a term not to exceed eight months. The agreement will be settled at its conclusion with the Registrant either receiving or paying a settlement amount based on the volume weighted average price of the Registrant’s common stock during the term of the agreement. The Registrant may elect to receive or pay any settlement amount in cash or shares of its common stock.

On August 20, 2007, the Registrant issued a press release announcing that its Board of Directors had restored the Registrant’s authorization for repurchase of shares of its common stock to a total of 10 million shares. In connection with the restored repurchase authority, the Registrant entered into an accelerated share repurchase agreement to purchase approximately $500 million of its outstanding common stock from Goldman Sachs & Co. (“GSC”). A copy of the press release is attached as Exhibit 99 to this Current Report on Form 8-K and is incorporated herein by reference.

(d) Exhibits (numbered in accordance with Item 601 of Regulation S-K).

2

(Former name, former address and former fiscal year; if changed since last report)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant is an accelerated filer (as defined in Rule 12b-2 of the Exchange Act).    Yes  x    No  ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12-b2 of the Exchange Act).    Yes  ¨    No  x

APPLICABLE ONLY TO CORPORATE ISSUERS:

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date: 89,435,550 shares of the Company’s Common Stock were outstanding as of September 30, 2005.

Table of Contents

(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: