Febrile seizures are the most common seizures in childhood and, like all seizures, can be frightening to witness. Therefore, it is not surprising that febrile seizures have been the focus of intense research with an extensive literature describing various preventative measures. In addition, there is also an extensive and sophisticated epidemiological literature delineating the natural history of this disorder in American and British children. For simple febrile seizures, the most common form of this disorder, the epidemiological studies demonstrate a generally benign natural history, making it unlikely that any preventative measure could improve the long term outcome for most children. Children with simple febrile seizures have a slight increased risk of epilepsy, but there are no studies that demonstrate that phenobarbital or other therapy can alter this risk. Daily therapy with phenobarbital or valproic acid can reduce the number of subsequent simple febrile seizures. However, as a recent Practice Parameter from the American Academy of Paediatrics concludes, the risk of adverse effects from daily therapy appears to outweigh the benefit of preventing the short term recurrence of simple febrile seizures. It is possible that in some families, where the occurrence of an additional simple febrile seizure would be particularly distressing, the routine use of oral diazepam during febrile illnesses might be appropriate.