Objectives Frequent recurrence of superficial bladder cancer is a major problem that impairs patients’ quality of life. We studied the current treatment of superficial bladder cancer, including the economic aspects of intravesical instillation. Methods A total of 138 superficial bladder cancers were assessed. The tumor characteristics and treatments were investigated during a mean observation period of 86 months by univariate and multivariate analyses. The costs associated with intravesical instillation of bacille Calmette-Guérin (BCG) and its side effects were subjected to cost-effectiveness analysis. Results Tumor histologic examination revealed grade 1 in 21 lesions, grade 2 in 60 lesions, grade 3 in 40 lesions, and unclassified in 17 lesions. The pathologic stage was Stage Ta in 85 lesions, T1 in 47 lesions, and Tis in 6 lesions. Univariate and multivariate analyses showed that intravesical instillation of BCG was the most significant factor preventing recurrence, and intravesical chemotherapy had no impact on recurrence. The 5-year recurrence-free survival rate was 78% and 28% for tumors with and without BCG instillation, respectively. The cost-effectiveness ratio of BCG instillation was approximately $3900/5-yr recurrence-free period. Conclusions Our results have indicated that BCG is an effective adjuvant therapy after transurethral resection of superficial bladder cancer in the current medical environment.