Acute stroke must be considered as an emergency with highest priority. The same is true for patients with transient ischemic attacks, given their high risk for following stroke events within the first 48 hours. Early brain imaging is essential for discrimination of either ischemic or hemorrhagic stroke. In acute ischemic stroke, rapid establishment of reperfusion is the major therapeutic goal. This is achieved by intravenous thrombolysis, in selected cases by an intraarterial approach with pharmaceutical and/or mechanical recanalization. The effect of successful reperfusion is highly dependent on time: the earlier, the better the odds for substantial clinical improvement. The recent extension of the time window for systemic thrombolysis to 4.5 hours must not result in any delays of diagnosis and treatment initiation! Stroke units with facilities for early etiological workup with according secondary prevention measures, for prevention and treatment of complications, and for early rehabilitation have been shown to yield the best outcome for all stroke victims.