Radiotherapy-associated bladder carcinoma was found in 3.7 percent of 244 cases of advanced urothelial carcinoma. Average age at diagnosis of the bladder tumor was 63.1 years, with a mean of 20.5 years between radiation treatment and diagnosis. All 9 patients presented with gross hematuria. Eight patients had transitional cell carcinoma, 7/8 (87.5%) also had vascular or lymphatic invasion, and 1 was adenocarcinoma. Mean survival was 15.4 months (range 1-40 mos.), with a 55.5 percent one-year disease-free survival after diagnosis. Four patients died of bladder tumor, 4 were alive with no evidence of disease, and 1 was alive with metastasis.