Neuronal migration anomalies(NMA) are congenital maiformations caused by insults to migrating neuroblast during the third to fifth gestational gestational months. We reviewed CT and MR findings of 17 patients with NMA to evaluate their usefulness in various migration anomalies. Of 17 patients, 9 had only CT, 3 had only MR, and 5 had both CT and MR. We diagnose 5 cases of schizencephaly, 3 cases of heterotopic gray matter, 3 cases of lissencephaly and 6 cases of polymicrogyria. Clinically, these patients presented with seizure, motor deficit and mental retardation. The main findings of each anomaly were as follows:(1) Schizencephaly was characterized by full-thickness cleft extending from cortical surface to ventricles with or without intervening CSF; (2) heter