OBJECTIVE We studied retrospectively the patency of grafts after coronary artery bypass grafting (CABG) using serial angiographies performed one year and five years after surgery. METHODS One hundred and nine patients who had available coronary angiographies at both one year and five years after CABG were included. Morphologic changes of anastomotic sites and grafts were traced in the same group of patients using the FitzGibbon grading system. RESULTS The arterial graft patency rate (FitzGibbon grade A+B) was significantly higher than the saphenous vein grafts at both one year (98.0% vs 82.4%, p<0.001) and five years (90.7% vs 80.2%, p=0.006) after surgery, respectively. The arterial graft patency rate was superior to vein grafts in the left anterior descending coronary artery territory at both one year (97.5% vs 82.0%, p=0.001) and five years (90.9% vs 78.0%, p=0.042) postoperatively. Other territories showed similar patency rates between arterial and vein grafts. The vein graft patency rate at five years postoperatively was lowest in the right coronary territory when compared with other territories. When the patency pattern was compared between postoperative years 1 and 5, the proportion of FitzGibbon grade B grafts increased significantly in the vein grafts (3.1% vs 7.5%, p=0.002), while that of arterial grafts remained stable (8.6% vs 7.3%, p=0.774). When the graft patency at postoperative year 5 was compared between patients with recurrent angina and those without, the patients with recurrent angina showed a higher proportion of FitzGibbon grade B grafts (19.2% vs 4.8% in arterial grafts, p=0.023; 20.5% vs 4.8% in vein grafts, p=0.003) and lower grade A grafts (65.4% vs 86.4% in arterial grafts, p=0.019; 43.6% vs 78.2% in vein grafts, p<0.001), and a lower vein graft patency rate (64.1% vs 83.0%, p=0.014). CONCLUSIONS The arterial graft patency rate was significantly higher than that of saphenous vein grafts, especially in the left anterior descending coronary artery territory, at one year and five years postoperatively. The decreased patency rate of the vein grafts, along with insulin-dependent diabetes mellitus, were associated with angina recurrence.