Since a first successful A-C bypass using saphenous vein graft was performed in 1970, eighty five patients with severe coronary heart disease were operated on in our clinic. Up to date, A-C bypass was carried out in sixty four cases, and aorto-coronary sinus bypass (Ao-Cs bypass) as an arterialization of the coronary venous system was done in one case in the group of angina pectoris. Three cases among sixty four patients who underwent A-C bypass and a case of Ao-Cs bypass died of low cardiac output syndrome postoperatively. Other two cases died of refractory arrhythmia and cardiomyopathy 6 years after surgery. The remaining fifty nine cases are doing well without any complications during follow up from ranging 2 months to 13 years (mean 3 years 4 months). Recently, no operative death was found during past 8 years with development of surgical technique and myocardial protection. Ventricular function (cardiac index, LVedp, Max LV dp/dt, EF, LVEDVI , double products at rest and during treadmill exercise test) disclosed good results especially in complete revascularization group. Graft patency had a close correlation between a diameter of the coronary artery at the anastomosis site and bypass graft flow after completion of bypass. Subsequently, a good patency rate (84%-86%) was obtained in cases with the coronary artery more than 1.5 mm in diameter. It could be concluded that A-C bypass was useful procedure to improve ventricular function as well as clinical symptoms and longevity of the life.