Mixed mesodermal sarcoma of the ovary is a rare clinical entity. To review the epidemiology, prognostic factors, and treatment results related to primary ovarian sarcoma at our center, a retrospective chart review of all patients referred for ovarian cancer was carried out from 1974 to 1994. Cases with confirmed pathologic diagnosis of primary mixed mesodermal ovarian sarcomas were selected, forming the present study group. Thirty-six charts were identified. The median age at presentation was 67.5 years. Findings at laparotomy demonstrated extraovarian metastasis in 33/35 patients. Total abdominal hysterectomy and bilateral salpingo-oophorectomy +/- omentectomy were performed in 34 patients, with 22 patients left with macroscopic residual disease after surgery. Follow-up adjuvant chemotherapy consisting of cisplatin and doxorubicin was administered to 29/36 patients. Follow-ups ranged from 1 to 11 years with a median of 2 years. As with epithelial ovarian cancer, residual disease after initial surgery is an important prognostic factor. Thirteen patients had a second-look laparotomy. Five patients were positive for disease. Eight patients, one of whom recurred, were histologically negative. The patients with positive second-look findings, as well as all those who recurred clinically, subsequently died within 12 months despite trials with different second-line chemotherapeutic agents. Survival analysis showed a median survival of 3 years among patients treated with combination cytotoxic chemotherapy. Primary ovarian sarcomas make up about 2-3% of all ovarian cancer cases seen in our center. These are often very aggressive tumors with widespread metastasis at the time of presentation, making optimal tumor debulking difficult. The combination of cisplatin and doxorubicin appears to have activity resulting in a survival of 35% at 5 years. Second-look surgery offers little helpful information on the management of these tumors.