Central neurocytoma is a rare intraventricular tumor recently accepted as a clinicopathological entity. A 21-year-old female was admitted with three-year history of episodic headaches and vomiting, and with rapid deterioration of her left vision over two weeks prior to admission. Computed tomography (CT) scan revealed a marked hydrocephalus and an isodense, mildly enhancing mass in the left lateral ventricle. On magnetic resonance imaging (MRI) scan, T1-weighted images revealed an intraventricular mass of slightly high intensity signal, which contained areas of low intensity signal representing multiple intratumoral cysts. The tumor showed a minimal enhancement with Gd-DTPA. A diagnosis of central neurocytoma was confirmed by an electron-microscopic study of a surgical specimen; there were numerous neuronal cell processes containing microtubules and dense-core vesicles, and a few small intercellular junctions were also identified.