Postmenopausal ovarian masses are not uncommon. Most of them are malignant due to inflammation and adhesion with the surrounding structures; these masses are fixed and torsion is not a usual phenomenon. We present a 73-year-old postmenopausal woman, parity five and five living issues with an acute abdomen. The examination revealed a 28–30-week size abdominal pelvic mass, which was confirmed to be ovarian in origin, with characteristics that indicated torsion on ultrasound Doppler. She underwent an emergency laparotomy with a total abdominal hysterectomy and bilateral salpingo-ophrectomy. Histopathology confirmed the diagnosis of serous cystadenoma. Ovarian torsion is a crucial differential diagnosis in postmenopausal adnexal masses presenting with acute abdomen. A high index of suspicion is required to diagnose and promptly manage women to improve the outcome.