A novel crystalline polymorphic form of ulipristal acetate useful as an agent for preventing and/or treating uterine leiomyoma and as a contraceptive, and a process for producing the crystalline polymorphic form are provided. The novel crystalline polymorphic form of ulipristal acetate is obtained by crystallization or transition in association with a specified solvent. The solvent comprises at least one member selected from the group consisting of water, an aliphatic hydrocarbon, an aromatic hydrocarbon, a halogenated hydrocarbon, a linear alcohol, an alkyl ether, an acetate ester, an alkyl ketone, an N-alkylacylamide, and an alkanenitrile.本發明提供可用作用於預防及/或治療子宮平滑肌瘤之藥劑及用作避孕劑之烏普司他醋酸(ulipristal acetate)之新穎結晶多晶型及產生該結晶多晶型的方法。該烏普司他醋酸之新穎結晶多晶型係藉由與指定溶劑有關之結晶或轉變來獲得。該溶劑包括至少一個選自由以下組成之群之成員:水、脂肪族烴、芳族烴、鹵代烴、直鏈醇、烷基醚、醋酸酯、烷基酮、N-烷基醯基醯胺及烷腈。
