Company Update

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): March 10, 2017 CULLEN/FROST BANKERS, INC. (Exact name of registrant as specified in its charter) Texas 001-13221 74-1751768 (State or other jurisdiction of incorporation or organization) (Commission File Number) (I.R.S. Employer Identification Number) 100 West Houston Street, San Antonio, Texas 78205 (Address of Principal Executive Offices) (Zip Code) (210) 220-4011 (Registrant’s telephone number) Not Applicable (Former name or former address, if changed since last report) Check the appropriate box below if the Form 8-K is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: ☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4 (c)) Item 8.01 Other Events Cullen/Frost Bankers, Inc. (the “Company”) is filing this Current Report on Form 8-K to file the computation of its ratio of earnings to fixed charges and its ratio of earnings to fixed charges and preferred stock dividends for each of the five years from 2012 through 2016 as an exhibit that is incorporated by reference into its Registration Statement on Form S-3 (File No. 333-214987). Item 9.01 Financial Statements and Exhibits (d) Exhibits Exhibit No. Description 12.1 Statement re: Computation of Ratios of Earnings to Fixed Charges and Earnings to Fixed Charges and Preferred Stock Dividends. 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. CULLEN/FROST BANKERS, INC. Date: March 10, 2017 By: /s/ Jerry Salinas Name: Jerry Salinas Title: Group Executive Vice President and Chief Financial Officer EXHIBIT INDEX Exhibit No. Description 12.1 Statement re: Computation of Ratios of Earnings to Fixed Charges and Earnings to Fixed Charges and Preferred Stock Dividends.