Thirty two patients-23 males and 9 females with a mean age of 52.5 years-underwent planned partial cystectomy for histologically proved muscle invasive bladder cancer. Twenty patients had transitional cell carcinoma and 12 had adenocarcinoma of the bladder. One patient had welldifferentiated, 18 had moderately differentiated, and 13 had poorly differentiated tumours. The tumour size was <2 cm in 7 patients, 2 4 cm in 19 patients, and >4 cm in 6 patients. Patients with single primary muscle invasive tumours situated in the upper half of the bladder were considered eligible for partial cystectomy . The presence of multicentric urothelial disease, of dysplasia, or carcinoma-in-situ in bladder mucosa away from the tumour on multiple random punch biopsies was considered contraindications to partial cystectomy. All patients underwent partial cystectomy with bilateral pelvic lymphadenectomy . The tumour-free margins of resection were confirmed by intraoperative frozen section examination. The bladder was closed primarily in all patients, although three patients required re-implantation of the ureter. No patient received adjuvant radiation or chemotherapy. Five patients had pathological stage B 1 (T2), 18 had B2 (T3A), and 9 had C (T3B) disease. No patient had metastatic pelvic lymph nodes. There was one postoperative death due to unrelated medical cause. Five patients had minor complications that resolved with conservative measures. All patients had adequate bladder capacity of >250 cc at 6 months after surgery, and none had symptoms attributable to reduced bladder capacity. The overall actuarial survival was 80.1% at 5 years. The 5-year survival for patients with stage T2 tumours was loo%, for stage T3A 88.5%, and for stage T3B 45.7% ( P = 0.028). The 5-year survival for patients with tumour size <2 cm was 100% compared to 83.1 % for 2-4 cm and 50% for size more than 4 cm (P = 0.078). There was no significant difference in survival for patients with transitional cell carcinoma (83.8%) and adenocarcinoma (74.1%) (P = 0.51 1). Patients with welldifferentiated tumours had a 5-year survival of 100% as compared to 94.4% for moderately and 53.5% for poorly differentiated tumours (P < 0.001). Fourteen patients relapsed-12 in the bladder and 2 in the lungs without relapse in the bladder. Of the 12 patients who relapsed in the bladder, 5 had noninvasive (stage Ta/Tl) relapses and were salvaged with transurethral resection of the tumours. Seven patients had invasive tumours at relapse that were related to tumour stage and grade. Four of these could be salvaged with radical total cystectomy , whereas the remaining