Cystic fibrosis is the most common, potentially lethal genetic defect in the Caucasian population. During recent years it has been increasingly associated with a number of hepatic and biliary abnormalities, of which chronic cholestatic liver disease is by far the most relevant. Plugging of intrahepatic bile ducts with inspissated secretions is thought to play a major role in the pathogenesis. Attempts have been made to provide uniform criteria to identify patients with early, possibly reversible, hepatic lesions, as well as to assess severity of liver disease. It has been estimated that bout 13% of cystic fibrosis patients present serum liver enzyme abnormalities, but prevalence of liver involvement is likely to be higher. Due to decreasing mortality from extrahepatic causes in cystic fibrosis and to the widespread use of laboratory tests and ultrasound examination, patients with minor degree of liver involvement will be increasingly represented in future. Oral bile acid therapy is promising, but its long-term benefits in terms of survival and prevention of major complications of liver cirrhosis remain to be established. Liver transplantation is the only potentially curative treatment for patients with advanced stage liver disease and mild pulmonary involvement.