Liver transplantation has revolutionized the outcome of metabolic liver diseases that are caused by defects in hepatocytes (e.g., Wilson's disease) or by excessive deposition of substrates secondary to their increased absorption (e.g., hemochromatosis). Early diagnosis and referral are the keys to successful outcome. The timing of liver transplantation for patients on medical therapy depends on a lack of biochemical and clinical evidence of improvement. Overall outcome following liver transplantation depends on the severity of multisystem involvement and preoperative decompensation.