The term "cerebral vasospasm" means "narrowing" or a contracted state of the cerebral arteries in vivo. Vasospasm following subarachnoid hemorrhage is an important cause of cerebral ischemia and is the most frequent serious complication in survivors of subarachnoid hemorrhage. This clinical article discusses the pathomechanism of vasospasm and rationale of various approaches to management. It has been shown that impairment of nitric oxide production and vasodilator function is an important mechanism associated with the pathogenesis of cerebral vasospasm. This explains the effectiveness of nitric oxide donors such as nitroglycerin as vasodilators. In the overall management of the patient with cerebral vasospasm, attention should be paid to the associated disturbances in the brain.