The aim of the present study was to determine the prevalence of hepatocellular carcinoma in adults with heterozygous alpha 1-antitrypsin deficiency and to assess the presence of possible co-risk factors for the development of hepatocellular carcinoma. Two hundred and forty patients with cirrhosis of different aetiologies and 130 patients with alpha 1-antitrypsin deficiency without evidence of chronic liver disease were investigated. Out of the 240 patients with cirrhosis, 61 patients (25%) were found to have alpha 1-antitrypsin deficiency, 36 patients (15%) had chronic hepatitis C infection, 50 (21%) had chronic hepatitis B and 24 (10%) had hepatitis C and hepatitis B infection. Thirty patients (12%) had cryptogenic cirrhosis and 39 (16%) alcoholic cirrhosis. The prevalence of hepatocellular carcinoma in patients with alpha 1-antitrypsin deficiency-associated cirrhosis was comparable to that of hepatocellular carcinoma in patients with cirrhosis of other aetiologies. Positive viral markers were found in 67% of the patients with alpha 1-antitrypsin deficiency-associated cirrhosis with hepatocellular carcinoma. In contrast, in the group of 130 patients with alpha 1-antitrypsin deficiency but without clinical and laboratory signs of chronic liver disease, none was found to have hepatocellular carcinoma (p = 0.001). Our results indicate that heterozygous alpha 1-antitrypsin deficiency-associated cirrhosis is a risk factor for hepatocellular carcinoma, but this is due to chronic liver disease and not due to the metabolic disorder itself.