Most strokes (85%) are ischemic. The central core of densely ischemic tissue is surrounded by a potentially salvageable “penumbral” zone amenable to thrombolytic therapy. Four major studies with recombinant tissue plasminogen activator (rt-PA) have shown that intravenous rt-PA is beneficial if used within a 3-hour timeframe by experienced centers in selected patients: 43% of patients are functionally independent at 30 days, early mortality is 13%, and the intracerebral hemorrhage rate is 3.3%. In a less evaluated procedure, intra-arterial thrombolysis, a thrombolytic drug is released directly into the occluded artery. The two methods can be combined. Backed by the hugely informative input of multimodal magnetic resonance imaging, thrombolysis now represents the most exciting challenge in vascular neurology, despite the formidable logistic constraints of the 3-hour treatment window...