Published medical evidence pertaining to the management of aneurysmal subarachnoid hemorrhage (SAH) was critically reviewed in order to prepare practice guidelines for this condition. SAH should be considered as a possible cause of all sudden and/or unusual headaches, and every attempt should be made to recognize mild SAHs, as they are still frequently misdiagnosed. The first test for SAH is computed tomography (CT), followed by lumbar puncture when the CT is negative for intracranial bleeding (the case in only several per cent of patients within 24 hours of aneurysm bleeding). Urgent cerebral angiography is necessary to detect the underlying cerebral aneurysm. The advantage of rapid diagnosis of SAH followed by early aneurysm repair is minimizing the risk of catastrophic aneurysm rebleeding. Early surgery for aneurysm repair is often possible and is recommended, unless the aneurysm location or size renders it technically difficult to expose in clot-laden subarachnoid cisterns beneath an acutely swollen brain. Aneurysm ablation is optimally accomplished with open microsurgery and clipping of the aneurysm neck, although other options include proximal parent artery occlusion, “trapping” of the aneurysmal segment of the artery, and embolization of thrombogenic materials (e.g., platinum “microcoils”) directly into the aneurysm dome using endovascular techniques. Neurological outcome following SAH is also optimized through the prevention of secondary SAH complications, and further management specific for ruptured cerebral aneurysms can include anticonvulsants, neuroprotectants, and various agents and techniques to prevent or reverse delayed-onset cerebral vasospasm. All patients with aneurysmal SAH should be treated with the calcium antagonist nimodipine, and in certain circumstances patients should receive anticonvulsants. Induced arterial hypertension, hypervolemia and in some instances percutaneous balloon angioplasty are recommended to reverse vasospasm causing symptomatic cerebral ischemia prior to cerebral infarction.