PURPOSE: We evaluated the outcome of repeat transurethral bladder tumor resection for high risk nonmuscle invasive bladder cancer before induction and maintenance bacillus Calmette-Guerin. MATERIALS AND METHODS: Included in the study were 151 consecutive patients with a mean age of 68.6 years (range 32 to 86) with primary high grade, nonmuscle invasive (Ta, T1 or CIS) bladder cancer. All patients underwent repeat transurethral bladder tumor resection and were shown by repeat resection to be tumor-free or have residual tumor before bacillus Calmette-Guerin. The bacillus Calmette-Guerin response was evaluated by disease recurrence and progression. RESULTS: A total of 70 tumor-free patients and 47 with residual tumor received bacillus Calmette-Guerin induction and maintenance therapy after repeat transurethral bladder tumor resection, of whom 84 (71.8%) were disease-free during followup. In the tumor-free group 11.4% of tumors recurred compared with 27.7% in the residual tumor group (p <0.05). Progression was noted in 5.7% of tumor-free cases vs 17.0% of residual tumor cases (p <0.05). Time to recurrence was significantly less in the residual tumor group than in the tumor-free group (17.8 vs 23.9 months, p <0.001). CONCLUSIONS: Tumor-free status at repeat transurethral bladder tumor resection improves the bacillus Calmette-Guerin response rate and delays tumor recurrence. During followup recurrence in residual tumor-free patients develop more likely as low grade lesions than in patients with residual tumor at repeat transurethral bladder tumor resection.