The present document is a third revision of the existing guideline. It should be considered as general guidance on the development of medicinal products for the treatment of epileptic disorders and should be read in conjunction with other EMA and ICH guidelines, which may apply to these conditions and patient populations. The main changes to the existing guideline include incorporation of the new classification / definitions of seizure types and epilepsies, the acceptance of add-on studies in support of a monotherapy claim on a case-by-case basis, the inclusion of new sections on neonates and status epilepticus and other changes related to paediatric developments. This guideline provides assistance for the development and evaluation of medicinal products for the treatment of epilepsy in adults and children. The scope of this document is restricted to treatment of seizures in epileptic disorder although there are some remarks concerning non-seizure features of epilepsy syndromes.