Non-puerperal uterine inversion is a rare clinical problem with only 150 cases reported. It usually results from a tumor implanted on fundus of the uterus. Uterine inversion associated with pelvic organ prolapse (POP) is extremely rare with only 1 case reported. A 74-year-old multiparous menopausal women was admitted to our hospital with the following condition: purulent vaginal discharge, voiding difficulty, lower abdominal discomfort, vaginal bleeding, protruding vaginal mass and POP. She was diagnosed as a POP with uterine inversion. After a posterior hysterotomy, vaginal hysterectomy, bilateral salpingoophorectomy and colpocleisis was performed and the pathological examination revealed a pyometra. We report a rare case of uterine inversion associated with POP and pyometra with a brief review of literature.