A 63-year-old man presented with headache. Magnetic resonance imaging showed a mass lesion homogeneously enhanced with gadolinium, which occluded the route from the third ventricle to the aqueduct. The patient underwent surgery for removal of the tumor via the right frontal transcortical-transventricular approach to the third ventricle via the transchoroidal route. Intraoperative diagnosis was meningioma. Total removal of the tumor was achieved in piecemeal fashion (Simpson grade 1). The histological diagnosis was meningothelial meningioma. The patient was discharged without neurological deficits. Third ventricle is a rare and difficult site to remove tumor totally. However, total removal was needed in this case of benign meningioma, so the operative strategy and the differential diagnosis before operation is considered to be very important.