Ovarian sarcomas represent less than 3% of all ovarian tumors. Leiomyosarcoma (LMS) is a rare subtype, accounting for only 0.1% of all ovarian sarcomas. We present a case of primary ovarian LMS in a 68-year-old multigravid woman. She was treated by total abdominal hysterectomy with bilateral salpingo-oophorectomy, followed by adjuvant chemotherapy. The prognosis of ovarian LMS is very poor. Although different treatment modalities like adjuvant chemotherapy and radiotherapy have been described, no clear benefit has been proven.