Hepatic dysfunction is a common metabolic complication of parenteral nutrition in both the pediatric and adult age groups. In infants, elevation of the serum direct bilirubin reflects intrahepatic cholestasis. In the adult lesion, elevation of alkaline phosphatase and transaminases reflect fatty infiltration. Although the causes are unknown, they are probably multifactorial and involve imbalances of administered nutrients. Hepatic dysfunction is nearly always self-limited and resolves following cessation of parenteral nutrition. Further research into assessment of exact nutrient requirements and a better understanding of the cellular effects of parenteral nutrition should lead to prevention of this complication.