Background. Recent reports suggest dramatic improvement in outcome using retrograde cerebral perfusion (RCP) during operations on the arch; however, most investigators have compared contemporary results with historic controls. The purpose of this study was to determine the impact of RCP within the same patient population and time period. Methods. From 1996 to 2000, 72 consecutive patients underwent an aortic arch procedure using hypothermic circulatory arrest (HCA) (31 acute dissection or rupture, 41 chronic dissection or aneurysm). Supplemental RCP was used in 36 patients, whereas 36 patients had HCA alone. The groups were similar in age, emergent status, and cardiopulmonary bypass time (p > 0.08), but HCA time was higher with RCP (40 ± 15 minutes versus 29 ± 14 minutes; p < 0.001). Results. Operative mortality was 10% ± 4% (±70% confidence limit), and adverse outcomes (death or cerebrovascular accident) occurred in 14% ± 4%, but there was no difference between HCA alone (8% ± 5%, 14% ± 6%) and HCA with RCP (11% ± 5%, 14% ± 6%) (p > 0.73). The incidence of transient neurologic dysfunction was also similar (HCA alone, 11% ± 5%; HCA with RCP, 17% ± 6%; p > 0.73). Multivariate risk factors for mortality included emergency operation and HCA time (p < 0.02). Risk factors for adverse outcome included emergency operation and atheromatous ascending aorta (p < 0.03). Risk factors for transient neurologic dysfunction included preexisting cerebrovascular disease and rewarming retrograde (femoral) rather than antegrade (through the graft) (p < 0.03). Conclusions. Supplemental RCP during HCA did not decrease mortality or neurologic complications. Retrograde rewarming through the femoral artery after completion of the distal anastomosis increased transient neurologic dysfunction. Therefore, RCP remains optional, but reperfusion should be antegrade to improve neurologic recovery.