Cismadinone acetate, also known as 6ñ-chloro-ô<sup>1</sup>-dehydro-17ñ-acetoxyprogesterone or as 6ñ-chloro-17ñ-acetoxypregna-1,4-diene-3,20-dione, is a steroidal progestin related to the 17ñ-hydroxyprogesterone derivatives which was never marketed. It is the acetylated form of cismadinone, which is also a progestin but, similarly to cismadinone acetate, was never marketed.