An 18-year-old man was admitted with a 1-month history of headache and disturbed visual acuity. Neurological examination revealed a visual field defect of bilateral inferotemporal areas. The endocrinological examination was normal. Magnetic resonance imaging (MRI) revealed a large cystic lesion in the anterior and middle skull base. Total resection was performed via a right frontal-lateral approach. At operation, a well-demarcated cyst pressed the optic nerve and the pituitary stalk, and attached to the wall of the third ventricle via a nodule. Histological examination confirmed a mature teratoma. His vision recovered and no recurrence was found during a follow-up period of 16 months.