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): September 13, 2013

CASEY’S GENERAL STORES, INC.

(Exact name of registrant as specified in its charter)

515/965-6100

(Registrant’s telephone number, including area code)

NONE

(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):

On September 13, 2013, Casey’s General Stores, Inc. (the “Company”) held its 2013 annual meeting of shareholders (the “Annual Meeting”). In addition to the election of three Class III directors, two other proposals were acted upon at the Annual Meeting, each of which is described briefly below and in detail in the Company’s definitive proxy statement for the Annual Meeting (the “Proxy Statement”). The matters voted upon and the number of votes cast for or against, as well as the number of abstentions and broker non-votes as to such matters, were as follows:

1. The following nominees for Class III directors were elected to serve three-year terms expiring in 2016 by a plurality of the votes cast at the Annual Meeting:

2. The appointment of KPMG LLP as the Company’s independent auditors for the fiscal year ending April 30, 2014 was ratified by a majority of the votes cast at the Annual Meeting:

3. In an advisory vote on the compensation of the Company’s named executive officers, as described in the Proxy Statement, the compensation of the Company’s named executive officers was approved by a majority of the votes cast at the Annual Meeting:

On September 16, 2013, the Company also reported August 2013 same-store sales results for stores open for one full year. Same-store sales for prepared food and fountain increased 11.9%, and grocery and other merchandise increased 10.6% in August 2013 compared to August 2012.

Same-store gasoline gallons sold increased 4.3% in August 2013 compared to August 2012. The gasoline margin was above the Company’s fiscal 2014 goal of 15.0 cents per gallon. The average retail price of gasoline sold during August 2013 was $3.44 per gallon.

The information contained in this Item is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section, and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing.

The exhibit accompanying this report is listed in the Exhibit Index attached hereto.

SIGNATURE

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.

EXHIBIT INDEX

The following exhibit is filed herewith: