BACKGROUND We previously reported that the average tumor growth speed estimated from clinical findings may be useful as a prognostic factor to determine the stage progression in superficial bladder cancer. Here, we examined the relationship between the dynamic estimation based on the average tumor growth speed and the static estimation based on the biological proliferative activity determined from bromodeoxyuridine (BrdU) and proliferating cell nuclear antigen (PCNA) indices in superficial bladder cancer. METHODS The subjects were 11 patients with recurrent superficial bladder cancer. The tumor growth speed was calculated by dividing all tumor volume at a certain recurrence episode by the duration until the recurrence. And then, the average tumor growth speed was determined individually by calculating mean tumor growth speed for all recurrence episodes. BrdU and PCNA indices were investigated by immunohistochemical staining. RESULTS There was a significant correlation between the average tumor growth speed and indices of PCNA and BrdU were statistically (Spearmen's rank correlation test; between the growth speed and PCNA index: p = 0.85, p < 0.01; between the average tumor growth speed and BrdU index: p = 0.71, p < 0.05; between BrdU index and PCNA index: p = 0.77, p < 0.05). The average tumor growth speed which was calculated based on clinical findings reflected the biological proliferative activities such as BrdU and PCNA indices. Furthermore, the values of all indices were higher in the invasive than in the non-invasive cases. CONCLUSIONS These findings suggest that the average tumor growth speed as the dynamic estimation is an important prognostic factor to determine stage progression in superficial bladder cancer.