We studied 608 consecutive cases of anti-HCV-positive chronic liver disease. In 358 patients the diagnosis was established by needle liver biopsy. In 250 patients with liver cirrhosis the diagnosis was made on the basis of the unequivocal clinical signs and the results of imaging procedures. Chronic HCV infection is usually observed in adults or elderly patients; the age of the patients steadily increases with the progression of the illness to the more severe stages. Jaundice was infrequent in patients with chronic hepatitis or early cirrhosis; clinical symptoms and laboratory tests are of little value in differentiating CPH from CAH or in detecting early cirrhosis. Serum aminotransferases were usually only slightly elevated in all stages of the disease. Despite the mildness of the hepatic cytolysis, the progressive reduction in serum cholinesterase and albumin concentrations and the progressive increase in the serum alkaline phosphatase activity indicate progressive failure in the hepatic function in the course of the illness. The histological study showed that steatosis, follicular portal inflammation and eosinophilic changes in the hepatocytes were prominent features of chronic HCV infection. In contrast, severe piecemeal necrosis without bridging was rarely observed.