A retrospective review of 1,518 cases of transitional cell carcinoma treated by supervoltage irradiation is presented. The majority of patients had recurrent disease after previous treatment. An appreciable salvage rate has been achieved. A “high risk” group for distant metastases has been identified (T3) and the suggestion is made that adjunctive therapy be employed to deal with occult metastases. The place of preoperative irradiation in Stage T2 tumours has been referred to. It is recognised that this is an ageing population. Many die not of their cancer but from other causes. It is difficult to compare these results with others published because of problems in selection and differences in staging the tumours. We wish to thank the numerous consulting urologists who have assisted in evaluating these patients. We thank also Miss Teresa Chua and Dr DeBoer for the statistical help. This study was done with a grant from the Ontario Cancer Foundation.