The prevalence of the anti-hepatitis C virus (anti-HCV) antibody and hepatitis B surface antigen (HBsAg) among 123 alcoholic patients with liver disease from our hospital and 44 alcoholic subjects from the local community was evaluated. By radio-immunoassay HBsAg was detected in 30.1% of alcoholic patients with liver disease, compared with 11.4% of alcoholic subjects from the local community (p < 0.05). The prevalence of HBsAg was 40.7% (11/27) in patients with cirrhosis and hepatocellular carcinoma (HCC), 31.5% (17/54) in patients with cirrhosis only, and 29.4% (5/17) in patients with other liver diseases. By enzyme-linked immunosorbent assay, anti-HCV antibody was detected in 30.9% of alcoholic patients with liver disease, compared with 2.3% of alcoholic subjects from the local community (p < 0.0005). The prevalence of anti-HCV antibody was 44.4% in alcoholic patients with cirrhosis and HCC, 29.6% in alcoholic patients with cirrhosis only, and 17.6% in alcoholic patients with other liver diseases. As the degree of liver damage advanced, the prevalence of either HBsAg or anti-HCV antibody, or both, being detected in these alcoholic patients increased significantly (p < 0.05). The serum ALT level was higher among alcoholic patients who had either HBsAg or anti-HCV antibody than those having neither (151 +/- 204 vs 62 +/- 47 IU/L; p < 0.005). All three alcoholic patients with chronic hepatitis had positive HBsAg or anti-HCV antibody. Histologic findings, except cells within sinusoids, were comparable between the alcoholic patients with or without superimposed hepatitis viruses.(ABSTRACT TRUNCATED AT 250 WORDS)