Congenital coronary arteriovenous fistula is relatively uncommon and widespread use of echocardiogram and selective coronary angiogram are being recognized with increasing frequency. The right coronary artery is most commonly involved and the fistulous communication is most common to right ventricle. Surgical correction is strongly recommended to prevent the development of congestive heart failure, angina, subacute bacterial endocarditis, myocardial infarction, and pulmonary hypertension, as well as coronary aneurysm formation, with subsequent rupture or embolism. We report two cases of coronary arteriovenous fistula originated from right coronary artery terminated in the right ventricle. These 8 year-old female and 7 year-old male patients had surgical interventions using cardiopulmonary bypasses.