To better define the acute liver disease complicating thermal injury, 81 burn patients were evaluated for hepatic damage. Clinical and laboratory evidence of hepatocellular injury was present as early as 24 hours after burn in 47 patients (58%). Patients with liver disease had a larger mean burn size (p less than 0.01) and greater mortality than patients with normal liver studies. The magnitude of initial enzyme derangements did not distinguish the survivors, but jaundice was associated with a poor prognosis. Seventeen of the 19 jaundiced patients (90%) died. The early occurrence of hepatocellular injury suggested that acute hemodynamic alterations were important etiologically. Intrahepatic cholestasis and jaundice developed later in septic or hypoxic patients and was accentuated by hemolysis and blood transfusions. In these patients, liver histology showed a nonspecific hepatitis. An increased risk of septic complications could not be attributed to the presence of liver disease. Late emergence of conjugated hyperbilirubinemia suggested an underlying septic process.