Aneurysmal subarachnoid hemorrhage accounts for a small percentage of strokes, but it is a significant contributor to the morbidity rate. The diagnosis is challenging and has devastating consequences if it is missed. Accurate initial diagnosis and management are critical to the outcome of the disease. The emergency clinician must have a high index of suspicion and a judicious approach to evaluating the chief complaint of patients with spontaneous subarachnoid hemorrhage (ie, headache). This review evaluates the literature and current evidence, including controversies and recent American Heart Association guidelines, to support a best-practice approach to the diagnosis and treatment of patients with spontaneous subarachnoid hemorrhage.