Tissue polypeptide antigen (TPA) is a marker of proliferative cellular activity. The aim of this paper is to demonstrate the production of this marker in bladder carcinomas and to study the biological behaviour in this type of patients. From September, 1992 to June, 1993, we studied 50 patients divided into two groups. The first group comprised healthy subjects and the second one comprised 30 patients with bladder carcinoma. In both groups, we determined the TPS in blood and tumoral tissue by RIA (TPS-IRMA Beki-Diagnostic AB). Our results demonstrated higher levels of TPS in tumoral tissue and blood than in healthy subjects (1887.83 and 197.33 vs 231.5 and 58.23 IU/ml) and higher levels of tissular and blood TPS for the undifferentiated tumors (989.66 and 231.5, 1748.2 and 210, 1842.6 and 219, 2010.7 and 220 IU/ml for Broders' classification 1, 2, 3 and 4).