This study was aimed at assessing the presence of c-met overexpression in human hepatocellular carcinoma and at determining whether this feature is associated with a definite clinical or pathological characteristic. Expression of c-met was determined by Northern-blot hybridization of a specific probe (human met proto-oncogene) in 18 tumoral and nontumoral liver samples obtained in 18 cirrhotic patients with hepatocellular carcinoma submitted to surgical treatment. Eight of the 18 hepatocellular carcinomas exhibited c-met overexpression, with an increase ranging between 2-fold and 10-fold when compared by densi-tometry with the surrounding liver. By contrast, in the remaining 10 cases c-met expression was almost identical to that of the surrounding nontumoral liver tissue. Overexpression of c-met was not related to either the age, sex, etiology or functional status of the underlying liver disease, or to the size of the tumor, to its differentiation degree or to the presence of pseudocapsule invasion and existence of additional neoplastic nodules. These data indicate that almost half of the human hepatocellular carcinomas exhibit c-met overexpression. Nevertheless, the biological relevance of this characteristic is not known. (Hepatology 1994;19:88-91).