Between 1950 and 1974, 35 men and 10 women underwent partial cystectomy for transitional cell carcinoma of the bladder. Indications, contraindications and the principles of technique for partial cystectomy as therapy for transitional cell tumors of the bladder are discussed. All patients were evaluated postoperatively, with cystoscopic examination every 3 months for 1 year, every 6 months for 3 years and then at yearly intervals if no tumors had been detected. None of the patients received preoperative irradiation. Eight ureters were re-implanted and 6 prostate glands were enucleated at the time of partial cystectomy. There was 1 death in the immediate postoperative period. Complications developed in 13 patients, 3 of which were considered major. When recurrences were noted appropriate therapy was performed as indicated. Irradiation was the most commonly used method to treat distant metastases. The over-all 5-year survival rate is 57.7% (26 patients). Thirty-four patients were followed for 10 years. The survival rate for this group of patients was 32.4% (11 patients). The results of this study correlate well with other published reports.