We treated a patient with acute stroke by clot lysis with urokinase. The drug was administered via an arterial catheter that had been positioned in the middle cerebral artery with the catheter tip embedded in the thrombus. The use of a microcatheter that is not flow-directed was essential to performing this procedure. Thrombolysis was successful, but an underlying high-grade vascular stenosis caused rethrombosis. Nevertheless, the techniques used in treating this patient are relatively uncomplicated. They make intracranial arterial thrombolytic drug infusions practical and are an important subject for further clinical evaluation.