Context: Arterial grafts are thought to be better conduits than saphenous vein grafts for coronary artery bypass grafting (CABG) based on experience with using the left internal mammary artery to bypass the left anterior descending coronary artery. The efficacy of the radial artery graft is less clear. Objective: To compare 1-year angiographic patency of radial artery grafts vs saphenous vein grafts in patients undergoing elective CABG. Design, Setting, and Participants: Multicenter, randomized controlled trial conducted from February 2003 to February 2009 at 11 Veterans Affairs medical centers among 757 participants (99% men) undergoing first-time elective CABG. Interventions: The left internal mammary artery was used to preferentially graft the left anterior descending coronary artery whenever possible; the best remaining recipient vessel was randomized to radial artery vs saphenous vein graft. Main Outcome Measures: The primary end point was angiographic graft patency at 1 year after CABG. Secondary end points included angiographic graft patency at 1 week after CABG, myocardial infarction, stroke, repeat revascularization, and death. Results: Analysis included 733 patients (366 in the radial artery group, 367 in the saphenous vein group). There was no significant difference in study graft patency at 1 year after CABG (radial artery, 238/266; 89%; 95% confidence interval [CI], 86%-93%; saphenous vein, 239/269; 89%; 95% CI, 85%-93%; adjusted OR, 0.99; 95% CI, 0.56-1.74; P=.98). There were no significant differences in the secondary end points. Conclusion: Among Veterans Affairs patients undergoing first-time elective CABG, the use of a radial artery graft compared with saphenous vein graft did not result in greater 1-year patency. Trial Registration: clinicaltrials.gov Identifier: NCT00054847 ©2011 American Medical Association. All rights reserved.