We assess the prognostic significance of bcl-2 expression, p53 mutation and ki-67 index for low grade, superficial transitional cell bladder carcinoma. The medical records of 93 cases of primary, low grade (24 G1, 69 G2), superficial (70 pTa, 23 pT1) transitional cell carcinoma of the bladder were reviewed. Association of bcl-2, p53 and ki-67 index immunoreactivity with tumor grade and stage was examined. Prognostic significance of tumor grade, pathological stage, bcl-2 expression, p53 mutation and ki-67 index in predicting tumor recurrence was assessed. Of the tumors 60 (70%) had p53 mutation and 9 (10.5%) expressed bcl-2. These 2 markers did not relate to tumor grade or pathological stage. Median ki-67 index was 10.9% and positively correlated with tumor grade. Recurrence was noted in 34.9% of patients with a median followup of 26 months (range 1 to 84). The ki-67 index was the only significant prognostic indicator in univariate and multivariate analyses. This marker can further distinguish grade 2 tumors with a favorable prognosis from those with an unfavorable outcome. The ki-67 labeling index is an independent predictor of tumor recurrence for patients with primary superficial, low grade bladder cancers.