A patient with known aortoiliac occlusive disease and hypertension suffered a cerebrovascular accident 6.5 min after the administration of intravenous dipyridamole during a 201Tl myocardial study. Despite aminophylline administration, the patient developed a completed stroke. The mechanism most likely responsible for precipitating this patient's stroke is dipyridamole-induced vascular steal. Although dipyridamole-201Tl myocardial imaging is relatively free of major complications, the morbidity and mortality associated with a cerebrovascular accident is significant. The possibility of precipitating a cerebrovascular accident during dipyridamole-201Tl imaging should be considered in all patients with significant risk factors for stroke before performing a dipyridamole cardiac study.