Background The primary ovarian sarcoma is a very rare malignancy. The objective of this study was to further investigate the clinicopathologic features and outcome in patients with primary sarcoma of the ovary.Methods Between 1988 and 2007, 24 patients with primary ovarian sarcoma who underwent treatment at Peking Union Medical Hospital were reviewed retrospectively. Response to treatment, progression and overall survival were analyzed.Results Patients with ovarian sarcoma had a mean age of (54.3±10.3) years, and 16 of them were postmenopausal.The most common symptom was abdominal pain, present in 14 patients. Of the 24 patients, 16 patients were pathologically diagnosed as carcinosarcoma (known as malignant mixed mesodermal tumor (MMMT)), 2 as ovarian leiomyosarcoma (LS) and 6 patients as ovarian endometrial stromal sarcoma (ESS). The patients in optimal debulking group had a median survival period of 28 months and 1-year survival rate of 71%. The patients in suboptimal debulking group had a significantly lower median survival of 6 months (P=-0.02) and 1-year survival rate of 29%. Among the patients,23 patients received chemotherapy and most of regimens were based on platinum, 3 patients received chemoradiation.The mean number of courses of combined chemotherapy was 6.6±5.0, and the response was unsatisfactory. The median survival for the entire group was 18.7 months. The one-year survival rate was 58%, and two-year survival rate only 29%.Conclusions Ovarian primary sarcoma has a poor overall prognosis. Optimal debulking surgery appears to be of prognostic significance. There is a clear need for further study to explore the role and the regimen of platinum-based chemotherapy in primary ovarian sarcoma.