The occurrence of a single seizure does not always require initiation of antiepileptic drugs. Risk of recurrent seizures should guide their use. In adults, key risk factors for recurrence are two unprovoked seizures occurring more than 24 hours apart, epileptiform abnormalities on electroencephalography, abnormal brain imaging, nocturnal seizures, or an epileptic syndrome associated with seizures. In children, key risk factors are abnormal electroencephalography results, an epileptic syndrome associated with seizures, severe head trauma, and cerebral palsy. The risk of adverse effects from antiepileptic drugs is considerable and includes potential cognitive and behavioral effects. In the absence of risk factors, and because many patients do not experience recurrence of a seizure, physicians should consider delaying use of antiepileptic drugs until a second seizure occurs. Delaying therapy until a second seizure does not affect one- to two-year remission rates. Treatment should begin with monotherapy. The appropriate choice of medication varies depending on seizure type. Routine monitoring of drug levels is not correlated with reduction in adverse effects or improvement in effectiveness and is not recommended. When patients have been seizure free for two to five years, discontinuation of antiepileptic drugs may be considered. For patients with seizures that are not controlled with these agents, alternative treatments include surgical resection of the seizure focus, ketogenic diets, vagus nerve stimulators, and implantable brain neurostimulators. Patients who have had a recent seizure within the past three months or whose seizures are poorly controlled should refrain from driving and certain high-risk physical activities. Patients planning for pregnancy should know that antiepileptic drugs are possibly teratogenic.