From July 1992 through January 1993, 11 patients with unstable angina received aorto-coronary bypass surgery at Dong-A University Hospital. There were 5 males and 6 females whose age ranged from 36 to 76 years old. Of the 11 patients, 3 were Functional class IL 5 were Functional class 111.3 were Functional class IV. Preoperative coronary angiography showed a significant stenosis of the left anterior descending artery in 9 cases, of its diagonal branch in I case, of the circumfiex artery in 3 cases, and of its obtuse marginal branch in 2 cases, of the right coronary artery in 4 cases, and of left main coronary artery in 3 cases. There were 4 cases of single vessel disease, 1 double vessel disease, 3 triple vessel disease and 3 left main disease. A single graft was placed in 1 patient, a double graft in 5, a triple graft in 2, and a quadriple graft in 3 patients. Left internal mammary artery plus saphenous vein graft were used in 4 patients. Postoperative complications were mediastinitis in 1, sternal instability in 2, pneumonia in 1, arrythmia in I case.