Levodopa was used orally (approximately 100 mg/kg) for the treatment of hepatic encephalopathy in 40 children, aged five months to 16 years. 15 of these patients had cirrhosis of the liver and 25 had hepatitis. The diagnosis was verified in 12 and 15 patients, respectively. L-dopa was combined with supportive treatment in each case. By the addition of levodopa to the treatment 44.7 % of the patients could be discharged from the hospital, compared with 4 of 20 patients (20 %) who were given the same supportive treatment, but no levodopa. Corticosteroid (I. V.) did not seem to be at all effective (which was administered to 16 cases in all). Exchange transfusion was used in the treatment of 17 cases of hepatic coma but was not found effective either.