Forty-two patients with malignant, mixed mesodermal tumors of the uterus were identified by retrospective chart review. Only 2 patients were premenopausal at the time of diagnosis. Six of the patients had previously received pelvic radiotherapy. Surgical/pathologic findings were inconsistent with clinical staging in 17 of the patients. Patients with stage I tumors were found to have extrauterine extension of tumor in 39% of the cases. Overall, 2- and 5-year actuarial survival rates were 40 and 18%, respectively. The surgical extent of disease was a major prognostic factor in patient survival (P = 0.006). Patients with tumors showing no invasion or invasion limited to the inner two-thirds of the myometrium also demonstrated a significant survival advantage as compared to those with deeper myometrial invasion (P = 0.02). However, no statistically significant relationship was demonstrated between survival and patient age, the nature of the sarcomatous element (homologous or heterologous), or the presence of cervical involvement. Patients with recurrent or persistent disease did poorly; only 4 patients have survived more than 1 year after documentation of recurrent disease. Two patients had prolonged disease stabilization with radiotherapy and cisplatin. Another patient with pulmonary metastases had a 6-month, complete response to cisplatin.