IMPORTANCE: To date, no study has defined the consequences of radial artery harvest based on a large number of patients in a prospective randomized trial. OBJECTIVE: To compare pain at the harvest site and functional changes associated with harvesting the radial artery vs saphenous vein for coronary artery bypass grafting. DESIGN, SETTING, AND PARTICIPANTS: This study compares the consequences of radial artery harvest with saphenous vein harvest in patients undergoing elective coronary artery bypass grafting procedures in Veterans Affairs hospitals. MAIN OUTCOMES AND MEASURES: Eleven hospitals screened 6148 patients, of whom 751 were included in this trial. We analyzed 2 variables: pain at the harvest site as measured on a scale of 0 to 100 (least to most painful) and hand performance testing. Patients included in this analysis had radial artery only (n = 80) or saphenous vein only (n = 337) harvest. Pain score, grip strength, and dexterity were measured before surgery and at 3 and 12 months after surgery. We adjusted for pain scores of the nonharvested extremity, age, whether the patient underwent endoscopic vein harvesting, and comorbid health conditions (smoking history, type 2 diabetes mellitus, hypertension, and heart failure). RESULTS: There was a significant difference in change of pain score at 3 months from the preoperative baseline between radial artery and saphenous vein groups after adjusting for covariates (P < .001) but not at 12 months (P = .07). No significant changes occurred in grip strength or dexterity from preoperative baseline to 3 and 12 months after surgery (P > .05). CONCLUSIONS AND RELEVANCE: The radial artery group reported significantly more pain than the saphenous vein group 3 months after surgery; however, similar levels of pain were observed in both groups at 12 months after surgery. Grip strength and manual dexterity were not changed by radial artery harvesting at 3 and 12 months. Copyright 2013 American Medical Association. All rights reserved.