Five cases scheduled for myocardial elective coronary artery bypass (CAB), who developed angina and ischemic electrocardiographic changes, after oral administration of dipyridamole (100 mg) are reported. Dipyridamole induced myocardial ischemia has been demonstrated in subjects with coronary artery disease, if this drug is administered intravenously. To our knowledge, only one study reported this side effect, after oral route, in four patients awaiting urgent CAB, for unstable angina. Based on our and other Authors experience, preoperative dipyridamole should be used with caution, especially in patients with unstable angina.