In 1996, the US Food and Drug Administration approved the use of intravenous recombinant tissue plasminogen activator (rtPA) for the treatment of carefully selected patients with acute ischemic stroke who could receive the medication within 3 hours of onset of symptoms. Since that time, the maximum time window for treatment has been expanded to 4.5 hours. Guidelines are available to provide recommendations and advice for the use of intravenous rtPA.1 As a result, rtPA has revolutionized the care of patients with ischemic stroke; now, patients with stroke may be successfully treated, and outcomes may be improved. Intravenous thrombolysis is now the engine that is driving emergency stroke care.