It is estimated that with more than 40 million adults in the United States having uncontrolled hypertension, the risk of developing ischemic or hemorrhagic stroke in this population is significant. In addition, roughly 1 of 100 patients with essential hypertension will experience a hypertensive crisis during their lifetime, and these accelerated hypertensive emergencies and urgencies complicate more than 27% of all acute medical problems in patients presenting to emergency departments (EDs) in the United States. Arterial hypertension, a prominent feature of acute stroke syndrome, usually declines spontaneously within a few days, but its presence at hospital admission or its acute development during hospitalization is often associated with worsening stroke outcome and early mortality. Control of hypertension in patients with subarachnoid and intracerebral hemorrhage, both forms of acute stroke, is directed at maintaining adequate cerebral blood flow to minimize ischemic damage and control intracerebral pressure while reducing the risk of rebleeding and developing cerebrovasospasm. Inappropriate lowering of the blood pressure in acute stroke may increase neurologic damage. However, adequate blood flow around the central area of the acute ischemic stroke or penumbra may result in ischemic cells being salvaged. Clinicians must be mindful that accelerated hypertension is associated with other types of patients seen in the ED, such as perioperative patients and patients with traumatic head injuries.