Immunoreactivity of bcl-2, p53, the epidermal growth factor (EGFr) and Ki-67 (MIB-1) proteins was assessed by immunohistochemistry in 185 patients with superficial bladder cancer (SBC) in order to evaluate their usefulness as indicators of tumor progression. Forty-one percent of the tumors were bcl-2 positive, 36% of them were positive for p53 (over 20% of nuclei), while 41% were positive for EGFr, and 30% of the tumors were MIB-1 positive (proliferation index > 15%). Immunoreactivity of all analyzed proteins was highly significantly related to tumor grade and stage. Tumors which were bcl-2, p53 or EGFr positive were also rapidly proliferative (MIB-1 score >15%). The obtained results suggest that all analyzed proteins may have prognostic significance in SBC. The prognostic value of the abnormal immunolabeling of the analyzed proteins will be established after an adequate follow-up period of this same cohort of patients.