In order to improve the effectiveness of information, we studied parents' perceptions and knowledge about fever and febrile seizures. A questionnaire study was carried out among the parents whose children (n = 230) participated in a randomized controlled trial of ibuprofen to prevent recurrent febrile seizures. Of the 230 parents, 181 (79%) responded to the questionnaire. Of all parents, 45% were afraid or very afraid of fever, which was strongly associated with being afraid of recurrent febrile seizures. Parents of children with a non-West European background were more afraid. The consequences of parental fear included frequent temperature measurements (25% measured five times per day or more), sleeping in the same room (24%) and 13% remained awake at night. Witnessing a febrile seizure is a frightening experience for parents; a majority thought that febrile seizures were harmful, because they look dangerous. Forty-seven percent thought that their child was dying during the initial febrile seizure. On the other hand, reassuring information may be helpful: 21% mentioned it as their reason to consider febrile seizures not harmful. We conclude that parental fear of fever and febrile seizures is a major problem with several negative consequences for daily family life. Adequate provision of information may reduce parental fear. We suggest that information about fever and febrile seizures should be provided to all parents, preferably during their contact with the providers of preventive healthcare. The parents of children with a non-West European origin need extra attention.