Over the past years the use of phenobarbital in so called "brain orientated neonatal intensive care" has gradually become established. It is the recommended drug for the treatment of seizures in term neonates. It also should be given to neonates who are being treated with curare like muscle relaxants and whose EEG may show paroxysmal activity. It is recommended to administer phenobarbital before curare is given. This may result in more effective mechanical ventilation. Seizures occurring in the premature baby can hardly be influenced. The prophylactic treatment of premature infants to avoid intraventricular haemorrhage is controversial. It is, however, generally accepted that full term babies with neonatal asphyxia should receive phenobarbital. Bacterial meningitis is also an indication for its use in a similar manner. A loading dose of 15-20 mg/kg body weight given intravenously is recommended. The plasma concentration of phenobarbital will usually reach therapeutic levels (15-30 micrograms/ml) within a few minutes of the injection and will hardly change during the following 48 hours. No other anticonvulsant drug should be used until the phenobarbital plasma level exceeds 40 micrograms/ml. As maintenance therapy a dose of 3-4 mg/kg/day is recommended. Due to the long plasma half-life (69-165 h) accumulation of the drug may be possible. It can be avoided if the dose does not exceed 5 mg/kg/day. The duration of therapy depends on the condition of the baby. In general early discontinuation after 1-2 weeks should be possible.