In selected patients with occlusive lesions of coronary arteries, aortocoronary bypass grafting has been effective in reducing anginal symptoms and in increasing the patients` longevity. Between May, 1977, and December, 1983, 41 patients with coronary occlusive disease received aortocoronary bypass surgery at Yonsei University Medical Center in Seoul. Thirty-three were male and 8 were female. Their ages ranged from 33 to 70 years [average 531.6 years]. Of the 41 patients, 11 suffered from stable angina, 30 suffered from unstable angina and 4 suffered from a variant type of angina. Eleven patients had 1 diseased vessel, 11 patients had 2 diseased vessels, 19 patients had 3 diseased vessels, and 5 patients had a diseased left main coronary artery. A single graft was placed in 5 patients, a double graft was placed in 17 patients, a triple graft was placed in 11 patients and a quadruple graft was placed in 8 patients. Nineteen patients received a sequential graft [40 sites of 20 vessels]. The average internal diameter of the grafted distal coronary artery was 2.380.15, 1.630.13 mm on the left side and 3.200.20, 1.830.21 mm on the right side. Two operative deaths occurred in the early years of our experience. The mortality rate was 4.87% and there were no late deaths. Of the 39 survivors, 30 [76.9%] were Functional Class I [free of symptoms without medication], 7 [17.9%] were Functional Class II and only 2[5.2%] were Functional Class III during the follow up period [653.75 patient-months]. On the basis of this experience, we conclude that coronary artery occlusive disease is occurring in increasing numbers in Korea. Therefore, a concerted effort is needed to detect this disease and to manage the increasing number of patients suffering from it.