UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): July 22, 2013

CAS MEDICAL SYSTEMS, INC.

(Exact name of Registrant as specified in its charter)

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))

Item 8.01. Other Events.

On July 22, 2013, CAS Medical Systems, Inc. (the “Company”) closed its previously-announced underwritten public offering of 5,200,000 shares of common stock, par value $0.004 per share, at a price to the public of $1.25 per share, resulting in net proceeds of approximately $5,879,000, after deducting the estimated underwriting discounts and commissions and estimated offering expenses. The Company intends to use the proceeds from the offering for operating costs, capital expenditures and for general corporate purposes, including working capital. Northland Securities, Inc. acted as the sole book-running manager for the offering.

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.