Patients with endometrial carcinomas who have undergone only radiation therapy represent a negative selection, because of the many concomitant diseases. In the author's group of 134 cases such patients were on average 7 years older than those who had undergone surgery. Even with computer-calculated opposing-field therapy with intracavity packing, radiation damage to the urinary tract must be expected. Of the 134 patients, 75 (55.9%) had pathologic urological findings following radiation therapy. The most commonly affected organ was the bladder (55.2%), followed by the kidneys (21.6%) and the ureter (7.5%). Radiation damage to the urethra could not be verified. The urological complications were hardly affected by the stage of the tumor, but considerably so by the time interval: the rate of urological complications was 68.9% higher after 5 years than after 1 year. Therefore, accurate statements concerning urological complications following primary radiation therapy for endometrial carcinoma cannot be made until 5 years have elapsed.