Treatment of a series of 194 patients with T3 (B2/C) tumors by radical radiotherapy, 5,000 to 5,500 rad in four weeks, produced a five-year survival of 40 per cent. Patients whose tumor completely disappeared after treatment (N = 97) had a five-year survival of 69 per cent. These results raise doubts about the necessity of performing elective cystectomy in patients who achieve complete response after radiotherapy, though the significantly better survival of partial responders who underwent salvage cystectomy emphasizes the need for an active policy of cystectomy once failure to respond completely to radiotherapy has been established and a need for techniques to give early indication of nonresponse to radiotherapy.