Background: The safety and efficacy of arterial composite grafts for total arterial revascularization have been demonstrated. The saphenous vein (SV) is a widely used graft because of its accessibility, sufficient length, and ease of manipulation. Our aim was to compare mid-term outcomes of saphenous vein Y-grafts with radial artery Y-grafts joined by anastomosis to the left internal thoracic artery. Materials and Methods: Records of off-pump coronary artery bypass grafting with composite Y-grafts based on the left internal thoracic artery technique in 552 patients were analyzed retrospectively. After propensity score matching, 79 radial arterial (RA) composite grafts (RA group) and 79 saphenous vein composite grafts (SV group) were compared. The duration of mean follow-up was $24.6{pm}14.6$ months (range, 1 to 55 months). Results: There were no differences in surgical mortality, all-cause mortality, or morbidity among the groups. Rates of 4-year survival were 91.7% and 96.3% in the RA and SV groups, respectively (p=0.519). The coronary reintervention-free survival rate and freedom from major adverse cardiovascular or cerebrovascular events were similar in the two groups (p=0.685, p=0.564). Conclusion: Construction of composite Y-grafts using the radial artery or saphenous vein showed similar mid-term results. Long-term follow-up and randomized trials will be needed to confirm our present conclusions.