Primary leiomyosarcoma of the broad ligament is a very rare and highly malignant gynecological tumor. The authors report a 61-yearold postmenopausal woman with signs and symptoms of malignant ovarian tumor. Preoperative magnetic resonance imaging (MRI) was interpreted as being suspicious for malignant tumors, such as an ovarian cancer or a leiomyosarcoma of the broad ligament, so laparotomy was performed. Macroscopically, the tumor was revealed with a 18 × 13.7 × 9.5 cm degenerated, multiple cystic part and solid whitish part arising from broad ligament which on histopathology proved to be leiomyosarcoma. To the best of the authors’ knowledge, primary leiomyosarcoma of the broad ligament has been documented in 21 reports or so, and no imaging findings are available. Here the authors present the MRI findings of primary leiomyosarcoma of the broad ligament.