We studied 104 patients diagnosed with hepatocellular carcinoma on the basis of pathological findings, in order to establish differences between patients with and without liver cirrhosis in addition to carcinoma. Among the former we also tried to identify differences between patients with previously diagnosed cirrhosis and those in whom cirrhosis was diagnosed at the same time as carcinoma. No significant differences were observed between patients in whom cirrhosis was diagnosed before or at the same time as carcinoma in relation to age, sex, etiologic factors or Child-Pugh grade. Differences were found with regard to motives for suspecting a tumor, frequency of splenomegaly, and platelet and leukocyte counts. No significant differences were found between patients with and without cirrhosis except in some laboratory findings (leukocytes, platelets, erythrocyte sedimentation rate and gammaglutamyl transpeptidase higher in the latter group, and alpha-fetoprotein higher in the former). There were no significant differences between cases of hepatocellular carcinoma that appeared as the first manifestation of liver cirrhosis and those that were diagnosed in patients with known cirrhosis. The clinical and biological differences between patients with and without cirrhosis can be explained by the associated chronic hepatic disease.