We evaluated 63 patients with superficial bladder cancer (pTa, pTl) who were treated with instillation of bleomycin +/- bacillus Calmette-Guerin (BCG) and administration of uraciltfutraful (UFT) for prophylaxis of tumor recurrence after transurethral resection (TUR). The patients were randomly assigned to groups A and B after transurethral resection by the closed envelope method. Group A (34 cases) was designed as continuous diluted intravesical instillation of bleomycin (120 mg/2,000 ml saline solution/day repeated for 3 days), instillation BCG (40 mg/40 ml saline solution/weekly 6 times) and UFT (400 mg orally/day for 2 years maximum). Group B (29 cases) was designed as the aforementioned minus BCG instillation. Cumulative non-recurrence rates in group A and group B were 80.1% and 72.1% at the time of three years, which revealed no significant difference between the two groups (p = 0.265, generalized Wilcoxon test). The high recurrent incidence of superficial bladder cancer is primarily due to the multifocal nature of the cancer or implantation of tumor cells at the time of the subsequent transurethral resection. The procedure was performed safely with no severe side effects. Our method might be useful to reduce the recurrences of superficial bladder cancer after transurethral resection of bladder (TUR).