Between March 1986 and November 1992, thirty-one patients with left main coronary artery stenosis[LMCAS, over 50% of cross sectional area] were revascularized at Seoul National University Hospital. The incidence of LMCAS was 20.8%[31/149]. The male:female ratio was 15:16. Age ranged from 39 to 70 years, with a mean age of 51 years. The anginal syndrome was composed of 23 unstable, 6 stable and 2 post-infarction angina preoperatively. There were sixteen isolated LMCAS, four ostial stenosis and eleven combined distal and /or right coronary artery stenosis. The degree of LMCAS was 50-74% in 21 patients[67.7%], 75-89% in one[3.6%] and 90-99% in 9[29.1%]. There was no case with 100% obstruction. Of the total patients with LMCAS, 11 patients received 4 distal anastomoses, another 11 patients had 3 distal anastomoses, and 8 patients needed 2 distal anastomoses. The overall operative mortality was 12.9%[4 /31], and the incidence of which was higher than the remaing group [6.8%, 8/118]. The causes of death were myocardial infarction[2 patients], ventricular arrhythmia[1 patient] and brain damage[1 patient]. All patients have been followed-up for average 28.9 months[1-76 months]. There was no late death. But one patients experinced anginal recurrence. In conclusion, making allowance for its notorious clinical results and relatively higher incidence in Korea, aggressive surgical techniques such as retrograce myocardial perfusion may be mandatory while we are in a learning phase.