To evaluate upper urinary tract tumor (UUTT) incidence and characteristics in 591 consecutive patients with low-, intermediate-, or high-risk superficial bladder cancer, who were followed up for at least 5 years or until death. From 1986 to 1992, 591 patients were treated for superficial bladder cancer: 216 patients with primary, solitary, low-grade (G1-G2), and low-stage (Ta-T1) superficial bladder cancer were considered at low risk of disease recurrence and treated with transurethral resection (TUR) alone; 182 patients with recurrent or multifocal superficial bladder cancer were considered at intermediate risk of disease recurrence or progression and treated with intravesical chemotherapy after TUR; 193 patients with carcinoma in situ, high-grade (G3) superficial bladder tumor, or intravesical chemotherapy failure were considered at high risk of disease recurrence or progression and treated with bacille Calmette-Guérin (BCG). After a median follow-up of 86 months (range 20 to 143), 2 (0.9%) of 216 patients at low risk, 4 (2.2%) of 182 patients at intermediate risk, and 19 (9.8%) of 193 patients at high risk developed UUTTs. The incidence of UUTTs is significantly higher in patients at high risk than in those at low risk (P = 0.0004, odds ratio = 11.6, 95% confidence interval [CI] 2.5 to 40.7) or at intermediate risk (P = 0.004, odds ratio = 4.8, 95% CI 1.5 to 17.2), or both (P = 0.000006, odds ratio = 7.3, 95% CI 2.6 to 20.3). The difference between patients at low risk and those at intermediate risk was not statistically significant (P = 0.5, odds ratio = 0.4, 95% CI 0.02 to 2.6). After a median time of 36 months (range 9 to 119) from UUTT diagnosis, 5 (20%) of 25 patients have died of the disease. The incidence of metachronous UUTTs is low in patients with superficial bladder cancer at low or intermediate risk of disease recurrence or progression and significantly higher for patients at high risk. Because UUTT is often asymptomatic, and mortality is high, frequent and lifelong examination of the upper urinary tract is suggested, with an annual intravenous urogram and urinary cytologic analysis every 4 months in patients with superficial bladder cancer at high risk of disease recurrence or progression.