Between 1983 and 1987, 79 patients received radiation therapy in combination with surgery for cancer of the endometrium. The pathology in all cases was adenocarcinoma. Most cases had deep myometrial penetration with moderate or poor differentiation. More than two-thirds of the patients had stage I disease. Twenty-two patients received preoperative radiation, and 57 patients received radiation following surgery. There were 10 recurrences in the 79 patients treated. Most recurrences were from distant disease, and there was only one case of an isolated pelvic recurrence. Adjuvant radiation is well-tolerated, and the failure rate in the pelvis is low, even with aggressive lesions.