Neuronal migration disorders are a group of malformations of the brain which primarily affect development of the cerebral cortex. Type 1 lissencephaly, the most common form of the neuronal migration disorders, is characterized by a flattened and thickened cerebral cortex with absent or reduced cortical gyri. Type 1 lissencephaly may manifest by variable clinical findings. A 4-years-old girl with convulsion and psychomotor retardation who was diagnosed to have agyria-pachygyria by magnetic resonance imaging was reported for rarely occurence.