Most ovarian and/or adnexal torsions occur in reproductive age and are less common in postmenopausal age. A 49-year-old menopausal woman presented to the Emergency Department with abdominal pain. She had a palpable pelvi-abdominal mass and abdominal tenderness on examination. Departmental ultrasound and magnetic resonance imaging (MRI) showed a large multilocular right adnexal cyst (15 × 12 cm) containing fluid with variable signal intensities on both T1 and T2 sequences (stained glass appearance) - most probably mucinous cystadenoma. The studied woman signed an informed consent form and agreed to exploratory laparotomy and adnexectomy. After the pre-operative investigations, which were done according to the hospital protocol, including CA-125 (26 IU/ml) and anaesthesia consultation, she was scheduled for laparotomy. At laparotomy an ovarian cyst originating from the right ovary was found with evidence of torsion of the infundibulopelvic and utero-ovarian ligaments (adnexal torsion). The right adnexa including the right ovary containing the ovarian cyst and the right fallopian tube was excised (adnexectomy). The histological examination of the excised adnexa confirmed the diagnosis of mucinous cystadenoma of the ovary. This report represents a rare case of an adnexal torsion in postmenopausal woman, to highlight that adnexal torsion can occur at any age and that the presence of ovarian mass or cyst predispose to adnexal torsion at any age.