Endometrial sarcomas (sarcomas of the endometrial stroma and mixed mullerian tumors) are rare tumors with a bad prognosis. Because of our experience in treating these tumors we have been able to make an analysis of epidemiology and the prognostic factors. We have treated 22 patients. The mean age was 61 years. There were 15 stage I, 3 stage II, 2 stage III, and 2 stage IV. 21/22 patients had a surgical resection of the primary tumor, 19/22 had pelvic irradiation after surgery with vaginal radiotherapy given for 14 patients. The actuarial survival rates at 3 and 5 years were 51 and 34%. 5/22 patients had pelvic recurrence, 6/22 had distant metastasis. In our study the prognostic factors were the stage and the histological subtype. Pelvic radiotherapy seems to improve the rates for survival. The main points for discussion are the need to have a definite histological diagnosis done after initial surgery. A CT scan of the lungs and a lymphangiogram must be performed before treatment. After surgery it appears necessary to give pelvic and vaginal radiotherapy. At the present time chemotherapy did not appear to improve survival.