A case of nonketotic hyperglycemic hyperosmolar coma occurred in an 11-year-old boy after hepatic transplantation. Focal seizures began shortly after revascularization of the transplanted liver and continued into the first day postoperatively. Blood glucose level was 652 mg/100 ml and osmolality 350 mOsm in the immediate period postoperatively. Seizure activity subsided, but his state of consciousness remained impaired with control of the hyperosmolar state. Postmortem examination 27 days later revealed diffuse subacute changes in the brain consistent with a toxic or metabolic origin. Correlation with glucose balance studies indicates that the patient with a liver damaged by ischemia will manifest intolerance to infused glucose, as well as a tendency toward hypoglycemia if glucose is not infused. Glucose supplementation after hepatic ischemia should be continuously monitored by repeated determination of blood glucose levels.