Coronary artery fistulas are infrequently encountered vascular communications that are either congenital or due to cardiac trauma. Most patients with these anomalies are asymptomatic, but late complications can occur and include congestive heart failure, myocardial ischemia, arrhythmias, and endocarditis. Therefore, many investigators have recommended surgical repair, even for asymptomatic patients. Although coronary arteriovenous fistulas pose many challenges to interventional cardiologists, early experiences suggest that these abnormal vessels can be successfully obliterated percutaneously; thus, the patient is spared the risks and morbidity associated with cardiac surgical intervention. Herein we present two cases that illustrate many of the technical issues involved in successful transcatheter embolization of coronary artery fistulas.