Intracranial nerve sheath tumors unrelated to the cranial nerve roots are extremely rare, and the origin of the tumors ar debatable. We report a case of pathologically-proven neurofibroma inside the lateral ventricle. A 49-year-old man presented with headache of 6 months duration, urinary incontinence, visual disturbance and right hemiplegia. Brain CT scan showed a well defined isodense mass with homogenous contrast enhancement and marginal calcification. At surgery the tumor was found to be 4cm-sized lobulated mass attached only to the choroid plexus. Histologically, the tumor masses consisted of fasciculating boundles of wavy spindle cells, with a considerable collagen laydown.