The SCC antigen expresses in the squamous epithelium during the process of a neoplastic transformation. This paper's objective is to evaluate the biological behaviour of SCC antigen in surface, deep, localized and spread malignant vesical carcinoma. To this end, 100 patients divided in two groups were studied. The first group consisted in 30 healthy subjects strictly selected and the second group comprised 70 patients diagnosed with transitional cell vesical carcinoma. SCC Antigen measurement was made by Radioimmunoassay (RIA, Abbott). Our results suggest that this tumoral antigen has no use as a prognostic factor in patients diagnosed with transitional cells vesical carcinoma, since serum concentrations suffer no change in relation to size, extent and degree of tumoral differentiation.