Liver disease is increasingly common in cystic fibrosis (CF). As new therapeutic options emerge, life expectancy increases and common hepatobiliary manifestations impact on quality of life and survival of CF patients. Hepatobiliary abnormalities in CF vary in nature and range from defects attributable to the underlying CFTR gene defect to those related to systemic disease and malnutrition. Today complications of liver disease represent the third most frequent cause of disease-related death in patients with CF. Here we review molecular and clinical genetics of CF, including genetic modifiers of CF-associated liver disease, and provide practical recommendations for genetic testing, diagnosis and treatment of hepatobiliary manifestations in CF.