All patients who present with subarachnoid hemorrhage should be admitted to the intensive care unit for close neurologic and cardiorespiratory monitoring. Neurosurgical consultation should be obtained if external ventricular drain placement, arteriography, or surgical planning are considered. Seizure prophylaxis, antihypertensive treatment for mean arterial blood pressure greater than 130 mm Hg, pain control, and bed rest are important measures for the prevention of rebleeding, which is associated with a high mortality rate. Standard deep venous thrombosis and gastrointestinal prophylaxis are recommended to prevent medical complications associated with critical illness. In patients with good-grade subarachnoid hemorrhage, early arteriography and definitive aneurysm management are recommended. The location and neck size of the aneurysm and the medical condition of the patient are factors in the decision to proceed with surgical rather than interventional aneurysm management. Postoperatively, clinical examination and transcranial Doppler ultrasonography are recommended for surveillance of vasospasm. If clinical or arteriographic evidence of vasospasm is present, hemodilution, hypertension, and hypervolemia (triple H) therapy should be instituted. If vasospasm is resistant to conservative measures, balloon angioplasty or intra-arterial papaverine therapy should also be considered.