We have studied 46 patients who underwent salvage cystectomy between March 1981 and June 1992 for persistent or recurrent carcinoma after radical irradiation for bladder carcinoma. The overall 5-year survival rate was 43%. There was a higher 5-year survival rate in patients with an incomplete response compared with those with a complete response to their prior irradiation (50 and 36%), in patients with grades 1 or 2 compared with grade 3 histology (75 and 28%), and in patients with T1 or T2 tumours compared with T3 tumours (59 and 32%). The median interval between commencing irradiation and performing cystectomy was 11 months. In the 25 patients with a prior complete response the median interval was 16 months; this was statistically significantly longer than in the 21 patients with an incomplete response (median interval 7 months). A worsening of tumour grade and category was found in some patients when comparing the findings at cystectomy with those prior to irradiation. This was consistently higher in patients with a prior complete response than in those with an incomplete response. There were 3 deaths and 12 non-fatal major complications due to the prior irradiation or surgery, with a mortality rate of 7% and an overall 5-year complications rate of 35%. Only one of the complications occurred in the 13 patients treated with conventional 2 Gy fractions alone (5 fractions/week). Their overall complication rate was statistically significantly lower than that of the others. Salvage cystectomy is indicated for selected patients with persistent or recurrent disease after radical irradiation for bladder cancer. The expectation of a survival rate similar to that found in patients treated with immediate cystectomy may not be justified.