Delayed type cerebral vasoconstriction (DCV) following aneurysmal subarachnoid hemorrhage is an important cause of permanent neurological injury and death. The mechanism of DCV remains unknown. Recently many investigators have used a new treatment for DCV involving the use of intraventricular sodium nitroprusside. We report upon a clinical case where a relatively large amount of sodium nitroprusside was intrathecally delivered by intraventricular catheter for the treatment for DCV.