Endometriosis, including endometriosis externa, endometrioma, adenomyois,adenomyomas, adenomyotic nodules of the uterosacral ligaments, andendometriotic nodules, such as scar endometriosis are effectively treated bythe intralesional administration, including transvaginal, endoscopic or opensurgical administration including via laparotomy, of a progestogen.Compositions therefor also are provided.