The epidermic growth factor (EGF) is a polypeptide which stimulates tissue proliferation. The mechanism of action takes place through an specific membrane receptor, known as the EGFR. Recent scientific contributions have allowed to know its implication in various tumoral processes (breast, ovary, bladder, etc), so that its expression may be used as a major prognostic factor. The objective of this work is to quantify and analyze the epidermic growth factor receptor (EGFR) in surface and invasive vesical carcinoma. To this end, 43 tissular samples divided in two groups were studied. The groups were: 1) Group 1 or control group, comprising 14 samples of "control" vesico-urothelial tissue, and 2) Group 2, assembling 29 patients with vesical carcinoma (17 surface and 12 infiltrant). All tissue samples underwent a process of homogenization and subsequent determination of membrane EGFR by means of radioimmunoassay (EGFR-Receptor Assay, Vienna Lab, Labordiagnostika GmbH). Our results demonstrate the expression of EGFR in both control and tumoral vesico-urothelial tissue in 100% of cases, with detection of significantly higher concentrations (p) in samples from vesical carcinoma than in those from control specimens (15.24 vs. 5.02 fmol/mg protein) and higher levels in infiltrant rather than in surface vesical carcinomas (18.92 vs. 11.4 fmol/mg protein).