We evaluated the prognostic significance of the Ki-67 labeling index (Ki-67 LI) in 75 patients with transitional cell carcinoma of the bladder who underwent radical cystectomy. Immunohistochemical staining of archival material was performed by the streptavidin-biotin method. Univariate survival analysis showed that Ki-67 LI (p < 0.001), histologic grade (p < 0.05), tumor stage (p < 0.001) and the number of positive lymph nodes (p < 0.001) significantly correlated with prognosis. Multivariate survival analysis indicated that the Ki-67 LI (p < 0.05), histologic grade (p < 0.01), tumor stage (p < 0.01), presence of lymph node metastases (p < 0.05) and use of neo-adjuvant therapy (p < 0.05) had independent prognostic value. The Ki-67 LI is an independent prognostic factor for patients with transitional cell bladder cancer treated by radical cystectomy.