The aim of this study was to compare the graft patency rates among patients who had a previous history of percutaneous coronary intervention (PCI) followed by coronary artery bypass grafting surgery (CABG) with the patients who had experienced CABG surgery alone. The 69 patients who were included in the study had a history of bare metal stent implantation prior to CABG (group 1). The coronary angiography results were compared with 69 patients who had a previous history of CABG (group 2). Graft patency rates of the left anterior descending artery and circumflex anastomoses are statistically significant for both groups, whereas the right coronary artery anastomoses are not statistically significant (p = 0.008; 0.009; 0.2). Graft patency rate of LIMA-LAD anastomoses was 43.9 +/- A 10.8 % in group 1 and 86.2 +/- A 6 % in group 2 for means of 60 months (p = 0.0001) and circumflex coronary artery anastomosis is 28.9 +/- A 0.9 % in group 1, 65.7 +/- A 10.8 % in group 2 (p = 0.0001) and the right coronary artery anastomosis is 37.2 +/- A 13.6 % in group 1, 56.4 +/- A 8.9 % in group 2 (p = 0.0001). The graft patency rates of coronary arteries without previous stent implantation were higher than the patients with previous stent implantation and experienced CABG. The results suggest that prior PCI may induce atherosclerotic events in the vessel that can adversely affect graft patency after surgery.