alpha-1-Antitrypsin deficiency due to homozygous Pi ZZ state is reported to be associated with cirrhosis and hepatocellular carcinoma (HCC); however, the role of heterozygous Pi Z state is not definitely known. In order to investigate the possible association, we studied the phenotypic distribution of alpha-1-antitrypsin variants (Pi) in 124 cases of HCC. Two thousand ten normal American Red Cross blood donors were studied as controls. Twelve patients with HCC had aberrant phenotypes, an incidence of 9.67% as compared to 8.36% among normal controls. Nine of 12 patients with HCC with aberrant Pi type had cirrhosis; 5 of the 9 had cirrhosis due to hepatitis B virus; 2 of the 9 had alcoholic liver disease with cirrhosis, and 2 had cryptogenic cirrhosis. The three patients with HCC arising in noncirrhotic livers who also had aberrant Pi phenotypes, had a relatively rare variety of HCC called fibrolamellar type. Z gene was found in five patients: all five were MZ. Incidence of MZ phenotype in HCC was similar to that of the normal control population (4.0% in HCC and 2.9% in the controls). However, 3 of 5 MZ were associated with fibrolamellar HCC. Another aberrant phenotype found among the patients with HCC was MF (fast moving) which occurred with an incidence of 2.41% as compared to none in the control group. In conclusion, we found no significant increase in the incidence of Z gene among 124 patients with HCC as compared to the normal population.