This article reports a case of a uterine torsion in an elderly woman who was diagnosed ovarian tumor pre-operation. An 83-year-old woman was admitted to the present hospital with acute lower abdominal pain, presenting with nausea and vomiting. Physical examination revealed that the general status was poor and a large abdominal mass about 20×25 cm was visible and palpable in the pelvic with tenderness. A preoperative diagnosis of torsion of an ovarian cyst was made and laparotomy was performed. Intraoperatively, a right ovarian cystic tumor about 30×30×25 cm was not twisted and the uterine corpus had undergone a 180-degree rotation along the transition between the corpus and the cervix uteri. Subtotal abdominal hysterectomy and bilateral salpingo-oophorectomy were carried out. The tumor was classified as a benign epithelial neoplasm of the ovary accompanied by hemorrhagic necrosis, not only of the cyst but also of the uterine corpus. The diagnosis and treatment of nongravid uterine torsion are deserving of discussion and study.