Objective: Although radial artery (RA) removal for coronary revascularization is considered safe, there is still considerable suspicion concerning adequate hand perfusion. We investigated the blood flow alterations in the donor forearm by quantitative perfusion scintigraphy tests in patients with RA conduits, and compared the results between the patients using different Allen test refill lengths. Methods: 50 patients undergoing coronary artery bypass graft surgery with RA grafts were investigated. Perfusion studies and a detailed physical examination of the donor hand were performed preoperatively, and repeated early before the patient was discharged and six months after operation. Forearm perfusion scintigraphy was performed by 370 MBq Technetium-99m Methoxyisobutyl isonitrile (MIBI). Perfusion index (PI) and blood pool index (BPI) were calculated by dividing the computed data from obtained images of the donor side by that of the non-donor side. Comparisons of the indices were initially performed within all patients, then through dividing the patients into three groups according to their Allen test refill length using ANOVA. Results: The incidence of any neurological symptoms was 32% in the early postoperative period. Preoperative measurements of both PI and BPI in all patients were not statistically significant when compared with the values obtained from the postoperative course. Indices of patients with long Allen test refill lengths were significantly lower than those of other patients' data in the first week after surgery. No statistical difference was observed at six months after the operation. Conclusion: According to our results, removal of the RA for coronary revascularization is safe. Although a significant decline in hand perfusion was observed during the early postoperative period in patients with long Allen test refill, compensatory mechanisms provide a dramatic amelioration in digital blood flow leading to good functional and neurological outcomes in the late course.