Metabolic liver diseases are a group of disorders which usually present in childhood with a wide-range of effects on the liver. Incidence is approximately 20% of pediatric and 4% of adult liver transplants performed for metabolic diseases. Metabolic disorders can be divided into 4 different groups according to the etiology: A. Primary metabolic defect is in the liver such as Wilson disease, α1–Antitrypsin deficiency, neonatal hemochromatosis, galactosemia, and glycogen storage disease type I, IV and alagille syndrome. B. Primary metabolic defect is in the liver and liver function is preserved such as familial amyloid polyneuropathy, primary hyperoxaluria type I, Crigler-Najjar syndrome type I, familial hypercholesterolemia, and urea cycle defects. C. Primary metabolic defect is extrahepatic such as nonalcoholic steatohepatitis (NASH), Gaucher disease, hereditary hemochromatosis, and porphyria. D. Systemic metabolic defect, liver also involved such as cystic fibrosis.