Epidermal nevus syndrome is a kind of neurocutaneous syndrome that is associated with epidermal nevus and a variety of congenital CNS disorders. Clinical presentations include seizures, paresis, mental retardation, and developmental delay. We report three cases with MR imaging and magnetoencephalography findings; one patient underwent ictal and interictal single photon emission CT. Both structural and functional imaging studies indicated that the frontal lobes had lesser involvement or were intact. One patient underwent hemispherectomy because of the medically intractable seizure. He remained seizure free with topiramate monotherapy.