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)

January 23, 2013

QUALITY SYSTEMS, INC.

(Exact name of registrant as specified in its charter)

18111 Von Karman, Suite 700

Irvine, California 92612

(Address of Principal Executive Offices)

(949) 255-2600

(Registrant’s Telephone Number, Including Area Code)

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 January 24, 2013, Quality Systems, Inc. (the “Company”) issued a press release announcing its financial performance for the period ended December 31, 2012. A copy of the press release is attached to this Form 8-K as Exhibit 99.1, which is incorporated herein by reference.

On January 24, 2013, the Company will host a conference call concerning its financial performance for the period ended December 31, 2012. The Company expects to furnish a copy of the transcript of the conference call as soon as it is available by amendment to this Form 8-K. The conference call may contain forward-looking statements regarding the Company and will include cautionary statements identifying important factors that could cause actual results to differ materially from those anticipated.

The information in this Item 2.02 of this Form 8-K, as well as Exhibit 99.1 attached hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

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Use of Non-GAAP Financial Measures

The Company from time to time discloses its Days Sales Outstanding (“DSO”), which is a non-GAAP financial measure. For the quarter ended December 31, 2012, DSO was 121 days. The Company calculates DSO as follows: Net revenue for the quarter is annualized (multiplied by four) and then divided by 365 days to yield an average daily sales amount. The balance of accounts receivable, net of any reserves for bad debts, is then divided by that average daily sales amount resulting in the DSO. For the quarter ended December 31, 2012, the calculation was as follows:

Quarterly Dividend

On January 23, 2013, the Company’s board of directors (the “Board”) declared a quarterly cash dividend of $0.175 per share on the Company’s outstanding shares of common stock, payable to shareholders of record as of March 15, 2013 with an anticipated distribution date on or about April 5, 2013. The $0.175 dividend is pursuant to the Company’s current policy to pay a regular dividend on the Company’s outstanding shares of common stock each fiscal quarter subject to Board review and approval.

The portion of the Company’s press release announcing the dividend is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

(d) Exhibits.

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SIGNATURES

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.

Date: January 24, 2013

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EXHIBITS ATTACHED TO THIS REPORT ON FORM 8-K

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