Multicentric development of transitional cell carcinoma in the urinary tract is well recognized. Of 169 male patients who underwent cystectomy for bladder cancer 18 (10.6%) demonstrated urethral cancer (all within 5 years after cystectomy). The risk factors involved in transitional cell carcinoma in regard to the occurrence of urethral cancer after cystectomy were examined by multivariate analysis. Characteristic patterns of bladder cancer in the cystectomy specimens were expressed by the grade, stage, number, size, location and gross pattern of the tumors. Significant risk factors in bladder cancer relating to the development of cancer in the retained urethra were papillary cancer, multiple cancers, and tumors in the bladder neck, prostatic urethra and prostatic gland. Among 19 patients with concomitant carcinoma in situ and/or multiple papillary tumors in the bladder who underwent simultaneous prophylactic urethrectomy with cystectomy in the same observed period 17 (89%) had no lesion in the resected urethra. The results of the multivariate analysis will be useful to avoid unnecessary prophylactic urethrectomy at cystectomy. However, further analysis and consideration of possible mechanisms of the secondary urethral cancer will be necessary to explain the discrepancy posed in the latter study involving 19 patients.