The genetic epilepsy with febrile seizures plus (GEFS+) spectrum is a complex concept to understand and derives from clinical genetic studies. In GEFS+, the clinician needs to understand the presentations that form part of the phenotypic spectrum to consider a familial epilepsy syndrome diagnosis of GEFS+. The characteristic electroencephalograph (EEG) signature is of irregular generalized spike-wave activity; however, this is not present in all affected individuals. All individuals with GEFS+ have seizures, although some have simple febrile seizures whilst others have more severe phenotypes. The main risk factor is fever in infancy and early childhood, however, some family members also have afebrile seizures of various types. As with all forms of epilepsy, seizures are more likely if the patient is tired or stressed. In the more severe phenotypes, multiple antiepileptic agents may be necessary. Often valproate and lamotrigine are useful for myoclonic-astatic epilepsy (MAE).