Dyke-Davidoff-Masson syndrome is a rare clinical syndrome consisting of hemiatrophy of cerebral hemisphere, enlargement of ventricles and prominent pneumatization of petrous pyramid of the temporal bone. Its clinical manifestations are hemiparesis, several types of seizure, mental retardation and other neurologic deficits. We experienced a case of Dyke-Davidoff-Masson syndrome in a four months old boy who visited to our department due to right side upper extremity weakness and infantile spasm. The brain magnetic resonance imaging showed marked hemiatrophy of left cerebral hemisphere and enlargement of left lateral ventricle. So with the review of literatures, we report a case of Dyke-Davidoff-Masson syndrome with infantile spasm.