Hepatic encephalopathy (HE) is the neuropsychiatric syndrome that occurs as a complication to liver failure in patients with acute or chronic liver disease. Mental status in this syndrome can range from subtle deficits to coma, with respiratory insufficiency and aspiration to the lungs. The mortality is high. The pathogenesis of HE is not clearly understood. One theory is that it reflects a metabolic disorder of the brain, developed from neuroactive nitrogenous metabolites in the gut that accumulate in plasma when there is an impaired hepatocellular extraction or porto-systemic shunting. Transient improvement of the condition is seen in a subgroup of patients after administration of flumazenil, a specific benzodiazepine antagonist. The group of patients with a positive response to flumazenil therapy may have a better prognosis. Flumazenil may be used in patients in the pretransplantation phase.