The possible deleterious role of febrile seizures on development is an old issue. It took a long time to realize that impaired development or occurrence of chronic epilepsy affected a very small minority of children with febrile seizures. These children either had pre-existing brain damage, specific genetic epileptic conditions, or seizure-induced brain damage from repeated prolonged seizures. Population-based (and not hospital-based) large prospective studies of children with simple febrile seizures have quite unequivocally shown that these do not cause any brain injury. Children with "simple" febrile seizures do not differ from controls in intelligence and behaviour at school age and the large majority do not develop epilepsy. In this article, the author revisits this old issue and explores why another study on this topic has been conducted.