Subarachnoid hemorrhage has cerebral and systemic consequences as well. The main purpose of admitting a patient in the Intensive Care setting is to provide protection, mainly by stabilizing fundamental physiological parameters. There are both systemic parameters and cerebral parameters to be controlled continuously, and cerebral parameters may consider the brain as a whole (global cerebral parameters as intracranial pressure) or may provide information on specific areas. Cerebral protection may be achieved only when multiparametric monitoring is instituted, since only the combination of many physiologic parameters provides information capable of identifying, and hopefully of treating, deleterious derangements.