Results of Operations

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):  October 15, 2025 CAPITAL SOUTHWEST CORPORATION (Exact Name Of Registrant As Specified In Charter) Texas 814-00061 75-1072796 (State or Other Jurisdiction of Incorporation) (Commission File Number) (IRS Employer Identification No.) 8333 Douglas Avenue , Suite 1100 Dallas , Texas 75225 (Address of Principal Executive Offices) (Zip Code) Registrant’s telephone number, including area code: ( 214 ) 238-5700   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): ☐ 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)) Securities registered pursuant to Section 12(b) of the Act: Title of Each Class Trading Symbol(s) Name of Each Exchange on Which Registered Common Stock, $0.25 par value per share CSWC The Nasdaq Global Select Market Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter). Emerging growth company ☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐ Item 2.02 Results of Operations and Financial Condition. On October 15, 2025, Capital Southwest Corporation (the “Company”) issued a press release announcing certain preliminary estimates of its financial condition and results of operations for its fiscal quarter ended September 30, 2025, as well as other information. A copy of such press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.    The information disclosed herein, including Exhibit 99.1 hereto, shall be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and shall be deemed incorporated by reference into the Company’s filings made under the Securities Act of 1933, as amended. Item 9.01 Financial Statements and Exhibits. (d)          Exhibits Exhibit No. Description 99.1 Press Release issued by Capital Southwest Corporation on October 15, 2025 104 Cover Page Interactive Data File (embedded within the Inline XBRL document) 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. Dated: October 15, 2025 By: /s/ Michael S. Sarner Name: Michael S. Sarner Title:   President and Chief Executive Officer