A variety of different inherited disorders may cause liver disease in adults. Recent advances in molecular genetics have improved our understanding of these diseases, such as the isolation and characterization of the genes responsible for Wilson disease, alpha1-antitrypsin deficiency, and cystic fibrosis. A candidate gene responsible for hereditary hemochromatosis has also recently been cloned. These scientific advances have important implications in the diagnosis, treatment, and screening of patients with genetic diseases and their families. We review the most common inherited liver diseases affecting adults, with emphasis on the clinical implications of recent molecular advances.