Introduction: We aimed to compare the effects of coronary lesion complexity assessed by SYNTAX (Sx) score on the clinical outcomes in patients who have received BMS versus undergone coronary bypass grafting. Patients and Methods: Our study population consisted of 459 consecutive patients received bare metal stents (n= 265) or coronary bypass grafting (n= 294). The complexity of coronary artery disease was assessed by Sx score. Sx score was classifi ed as tertiles, as follows: low Sx score (? 22), intermediate Sx score (23-32) and high Sx score (? 33). Results: Throughout the study, the intermediate-term incidence of any revascularization was signifi cantly higher in the percutaneous coronary intervention group compared with the coronary bypass grafting group for both overall group and Sx tertiles. The intermediate-term incidence of death from any cause was comparable between the treatment groups in patients with low and intermediate Sx tertiles. However, in patients with high Sx tertile, the intermediate-term incidence of death from any cause was signifi cantly higher in percutaneous coronary intervention group compared with coronary bypass grafting group. In the overall population, adjusted [hazard ratio, 95% CI: 0.88 (0.38-2.05), p= 0.780) risks for death from any cause were consistently comparable between percutaneous coronary intervention and coronary bypass grafting, whereas adjusted [hazard ratio, 95% CI: 0.12 (0.05-0.30), p