We report an intraventricular cyst in a 2-year-old boy who had myoclonic jerks of the extremities. The cyst had no communication with the ventricular system or subarachnoid space. Total removal of the cyst adhering to the choroid plexus was accomplished. The glial cyst wall was lined in part by flattened or cuboidal epithelium. The preoperative and postoperative computed tomographic scans and magnetic resonance images are presented, and congenital benign cysts in the lateral ventricle are reviewed and discussed.