Background Dislodging of preexisting cardiac thrombi has been a reported but unconfirmed cause of embolic strokes after thrombolytic therapy for myocardial infarction. Case Description An 82-year-old woman was admitted with congestive heart failure. Initial echocardiogram demonstrated ventricular thrombi. Three days later she experienced an inferior wall myocardial infarction, and intravenous streptokinase was administered. Six hours later she abruptly developed a global aphasia with a dense right hemiparesis. Repeat echocardiogram did not show any thrombus. Conclusions Thrombolytic therapy may have caused embolization of ventricular thrombi. Cardiac conditions that predispose to embolic strokes are not established contraindications to thrombolytic therapy. The potential for thrombolytic therapy to produce embolization in patients with preexisting cardiac mural thrombi should be evaluated.