Objective: We studied the postoperative 1-year results after off-pump coronary artery bypass surgery (OPCAB) with one or more saphenous vein grafts. Methods: We compared the clinical and angiographic results of 833 patients who underwent OPCAB between 1998 and 2004. Group 1 patients (n = 135) received one or more vein grafts. Group 2 patients (n = 698) received total arterial grafts. Coronary angiographies were performed early postoperatively (n = 804, 1.6 AE 1.5 days), and 1 year postoperatively (n = 671, 12.1 AE 4.2 months). Results: There were no significant differences in patient characteristics, operative mortalities, and morbidities between the two groups ( p = ns). Both the early postoperative and 1-year angiographies demonstrated significantly lower overall graft patency rates in group 1 than in group 2 (early: 90.9% vs 99.1%, p < 0.001; 1 year: 78.8% vs 95.1%, p < 0.001), which might be affected by the lower vein graft patency rates in group 1 (early: 86.4%; 1 year: 67.9%). There was no difference in the 1-year patency of internal thoracic arteries between the two groups (94.3% vs 95.6%, p = 0.402). Multivariate analysis demonstrated the use of vein graft (Odds ratio = 5.204, p < 0.001) as an independent predictor of graft failure during the first postoperative year. Target vessel revascularization rate during the postoperative 1 year was significantly higher in group 1 than in group 2 (7.4% vs 2.0%, p = 0.002). Conclusions: Our study revealed that saphenous vein graft use in OPCAB independently predicted the graft failure while increasing the target vessel revascularization rate during the first postoperative year. Exclusive arterial revascularization would be a preferable strategy in OPCAB. #