A total of 23 patients presenting with multifocal superficial bladder cancer and concomitant in situ transitional cell carcinoma of the prostatic urethra (mucosal in 19 and ductal in 4) underwent transurethral resection and intravesical bacillus Calmette-Guerin therapy. Median followup was 51.6 months (range 6 to 105 months). Of the 23 patients 13 (48 per cent) had a complete response with a median followup of 43.7 months without recurrence. Progression of some type (local, muscle invasion or metastasis) occurred in 10 patients (44 per cent); none occurred in the prostatic urethra. Median interval free of progression was 55.7 months; 7 of 10 patients required cystectomy for progression or refractory disease in the bladder (prostate negative for transitional cell carcinoma). A trial of complete transurethral resection plus intravesical bacillus Calmette-Guerin is a viable alternative to immediate radical cystectomy for patients with mucosal and/or ductal involvement of the prostatic urethra with in situ transitional cell carcinoma.