Epilepsy is a common disorder of neurological system in children.Inborn errors of metabolism (IEMs) is one of an important etiology of epilepsy.Seizures may be the first and the major presenting feature of IEMs.IEMs are a relatively rare cause of epilepsy,but their recognition and diagnosis is very important because several disorders are treatable.This review will concentrate on diseases where epilepsy is the predominant clinical manifestation and especially where the disease course can be positively influenced by specific metabolic therapies.