Cystectomies performed in 88 patients with bladder cancer in the course of 20 years had perioperative complications in 47%, mortality in 11%, with a decreasing tendency in the last 10 years. The extent of infiltration of the removed tumours was pT1 in 14 cases, pT2 in 14 cases, pT3 in 47 cases, and pT4 in 13 cases. Regional lymph node metastases were present in 11 cases (12.5%). Three-year survival was 50%, while five-year survival was 44.4%. Twenty-three patients (26%) died because of tumour recurrences. With increasing infiltration of the bladder wall lymph node metastases and tumour-related mortality also increased, while survival decreased. On the basis of the significant differences encountered in the survival and tumour-related mortality of patients with T3a and with T3b tumours, the distinction between the two groups with respect to therapy and prognosis is justified. In T3a tumours cystectomy is applied as monotherapy, while in T3b tumours adjuvant chemotherapy is also indicated. The prognosis of tumours extending beyond the bladder muscles is extremely unfavourable, with the exception of bladder cancers infiltrating the prostate, the removal of which may result in lasting survival in a part of the cases.