Hypertension is the single most important risk factor for all types of stroke: ischemic stroke, intracerebral hemorrhage, and aneurysmal subarachnoid hemorrhage. Epidemiologic studies over the past 30 years have demonstrated a dramatic reduction in the incidence and mortality of all stroke types with good control of hypertension, and it appears that all effective antihypertensive agents have similar efficacy in their ability to reduce stroke risk. In addition, it appears that acute treatment of hypertension in the setting of intracerebral hemorrhage and subarachnoid hemorrhage is beneficial, but it is still uncertain in the setting of ischemic stroke what level of blood pressure will result in the best possible outcome.