Aneurysmal subarachnoid hemorrhage (SAH) is a devastating neurological syndrome, which occurs at a rate of 3-25 per 100,000 population. Smoking and hypertension are the most important risk factors of subarachnoid hemorrhage. Rupture of cerebral aneurysm leads to rapid spread of blood into cerebrospinal luid and subsequently leads to sudden increase of intracranial pressure and severe headache. Subarachnoid hemorrhage is associated with neurological (such as re-bleeding and vasospasm) and systemic (such as myocardial injury and hyponatremia) complications that are causes of high mortality and morbidity. Although patients with poor-grade subarachnoid hemorrhage are at higher risk of neurological and systemic complications, the early and aggressive management of this group of patient has decreased overall mortality by 17% in last 40 years. Early aneurysm repair, close monitoring in dedicated neurological intensive care unit, prevention, and aggressive management of medical and neurological complications are the most important strategies to improve outcome.