A coronary arteriovenous fistula represents an abnormal communication from a coronary artery that may enter any cardiac chamber, a pulmonary artery, the coronary sinus, the superior vena cava or the pulmonary vein. We had a successful experience with 46 year-old male who complained exertional dyspnea[NYHA classification II] and anginal pain since 5 years ago. In intensive study of cardiac catheterization and coronary cineangiography, multiple bilateral coronary arteriovenous fistulas and mitral stenoinsufficiency with left atrial thrombi were recognized. The coronary arterio-venous fistula of left coronary artery was revealed large tortuous aberrant vessels that were connected between just distal portion of first diagonal branch of left anterior descending artery and main pulmonary artery. Other fistula was small tortuous vessel which was originated from left atrial branch of left circumflex artery, was drained into left atrium. The fistula of right coronary artery was communicated conal branch of right coronary artery to main pulmonary artery. But there was no 0y step-up in the right cardiac catheterization. The operative procedure were suture-ligation of draining orifice of coronary arteriovenous fistula in main pulmonary artery, mitral valve replacement[Ionescu-Shiley 25mm] with removal of left atrial thrombi and plication of left atrium under the extracorporeal circulation. The postoperative course was uneventful without any complication and discharged without problem at 17th postoperative days.