Alpha-1-antitrypsin deficiency is a common autosomal recessive disorder associated with premature development of emphysema, liver cirrhosis and hepatocellular carcinoma. This article reviews the existing literature on alpha-1-antitrypsin deficiency, with an emphasis on recent developments. A description of the protein, gene structure and function of alpha-1-antitrypsin as well as clinical aspects are presented. Treatment issues are addressed and a framework for the diagnostic workup and management of patients with alpha-1-antitrypsin deficiency and chronic liver disease is provided.