During a 21-year period, 66 patients with uterine sarcomas were treated at California Medical Center. Histological diagnoses were mixed mesodermal sarcoma in 32 patients (48%), leiomyosarcoma in 24 (36%), and endometrial stromal sarcoma in 10 (15%) patients. The majority of patients (73%) had Stage I tumors. The treatment consisted of surgery alone in 27 (41%), surgery in combination with radiation therapy in 36 (55%), and radiation therapy alone in three (4%) patients. The overall 1-, 2-, and 5-year actuarial survival was 74%, 57%, and 38%, respectively. The 1-, 2-, and 5-year actuarial survival for the 27 surgery alone patients was 73%, 50%, and 25%, which compared with 75%, 61%, and 44% for the 36 surgery plus radiation therapy patients (P = 0.12). The disease-free survival was better for the surgery plus radiation therapy patients, as compared with the surgery alone group (38% vs. 18% at 5 years, P = 0.081). The 5-year survival by histology was 70% for the 10 endometrial stromal sarcoma patients, 40% for the 24 leiomyosarcoma patients, and 23% for the 32 mesodermal sarcoma patients (P = 0.064). As expected, survival depended on the stage of disease (P less than 0.0001). Treatment failure was observed in 35 (53%) patients, which included 9 (14%) with failure in the pelvis. There was no difference in the incidence of failure among patients in the three treatment groups and also in the three histologic groups. There was, however, a significant difference in the incidence of pelvic failure between surgery alone and surgery plus radiation therapy patients. In the 27 surgery alone patients, nine (33%) relapsed in the pelvis, whereas none of the 36 surgery plus radiation therapy patients had locoregional failure, P less than 0.0001. Adjuvant radiation therapy is an important treatment in the management of patients with sarcoma of the uterus.