What is the rationale for the treatment of an epileptic seizure? More specifically, should a first seizure be treated as soon as it is diagnosed or should one defer treatment until a second seizure occurs? Several studies indicate that the risk of a second (unprovoked) seizure is <50%, but studies vary in methodology and most have reviewed outcome in children only. Also, many patients were maintained on antiepileptic drugs (AEDs) during these studies, meaning that the risk for seizure recurrence was perhaps underestimated compared with the risk if untreated. Most neurologists recommend waiting for a second seizure in order to avoid complications of medications that might prove to be unnecessary. Several large studies show that delaying treatment until a second seizure occurs does not worsen the course of epilepsy or likelihood of eventual seizure control. Seizures attributable to an acute illness ('acute symptomatic', provoked seizures) usually resolve with treatment of the underlying illness and thus long-term AEDs are often unwarranted. Nevertheless, seizures arising in certain circumstances are more likely to recur and there are special considerations for patients with strokes, tumours, infections and dementia, and also after head injury or neurosurgery. Patient preferences with regard to risk and benefit also enter into the decision on whether to initiate AED treatment after a single seizure.