Neonatal seizures are treated with phenobarbital and prolonged treatment does not prevent postneonatal epilepsy. The authors documented factors influencing phenobarbital use and determined whether published data changed practice. A total of 83 neonates with symptomatic seizures, clinical or electrographic, were evaluated for treatment, incidence of postneonatal epilepsy, and associated factors. Median phenobarbital treatment was 81 days. Nineteen children (23%) developed postneonatal epilepsy. Longer duration of seizures and an infectious etiology were associated with postneonatal epilepsy suggesting no impact on duration of phenobarbital treatment. Treatment duration was associated with duration of seizures and use of a second antiseizure medication. This study supports early discontinuation of phenobarbital and suggests providers utilize factors such as use of a second antiseizure medication and time to seizure control to determine phenobarbital duration, despite prior studies suggesting no impact of treatment length.