The case of a 32-year-old Japanese man with an expansile supratentorial neurenteric cyst is described. The initial MRI revealed a left frontal extraaxial mass lesion 20 mm in diameter that showed marked expansion to 32 mm and change in its signal intensity 13 months later. Fifteen months after his visit, the patient fell into status epilepticus and underwent surgery. The cyst wall was excised, and the cyst content was totally removed. The cytology of the cystic content and pathological findings of the cyst wall were compatible with the diagnosis of neurenteric cyst. Our literature search revealed that in 86% of the patients with this lesion, the lesion was involved in the occurrence of epilepsy during the perioperative period. When a neurenteric cyst is diagnosed, shunt surgery should be avoided to prevent migrating spread of neurenteric cells.