Epilepsy may be acquired or inherited. At least one half of epilepsy is genetic in origin; this figure is likely higher in children regardless of whether seizures are generalized or partial. Inherited epilepsies are classified as benign, cryptogenic, or symptomatic depending on associated clinical, electrographic, and neuroimaging features. To date, genetic mutations in the idiopathic inherited epilepsies affect channel function within the central nervous system; genes underlying symptomatic epilepsies are more heterogeneous. Accurate diagnosis of an inherited epilepsy syndrome provides useful prognostic information; it also may help guide diagnostic evaluation, including request for specific gene testing. In the near future, the relationship between genetic defect and response to specific anticonvulsants may also be better defined.