Alpha1-antitrypsin concentrations and phenotypes were determined in groups of patients with chronic active liver disease and primary biliary cirrhosis. The concentrations of alpha1-antitrypsin were above normal values in both groups; the patients with primary biliary cirrhosis had higher concentrations than those with chronic active liver disease. The prevalence of common phenotypes in these two groups did not differ from that in a sample of healthy blood donors from this institution of from a large Norwegian sample. We interpret our data as disputing the view that alpha1-antitrypsin phenotypes, other than Z. significantly predispose adults to hepatic cirrhosis.