Background: Renin-angiotensin system (RAS) blockers have shown superior results to an old beta-blocker, atenolol, despite of similar reduction of peripheral blood pressure (BP). The different impact on central hemodynamics was considered as one of the plausible mechanisms to explain those. But, few comparative studies with newer beta-blockers and RAS blockers were performed. We aimed to compare the central hemodynamic effects of losartan and carvedilol in a randomized, open-label study. Methods: In 201 hypertensive patients entered, 182 patients were analyzed in the present study. We measured aortic augmentation index (AIx) and central BP using pulse wave analysis and aortic pulse wave velocity (PWV) at baseline and after 24-week treatment with losartan- or carvedilol-based regimens. Results: Brachial BPs were reduced similarly in the two treatment groups. After 24 weeks, aortic PWV was increased (0.28짹1.29 m/s, p<0.05) and AIx was decreased (-5.03짹16.29%, p<0.01) in patients treated with losartan, whereas aortic PWV and AIx were unchanged (-0.12짹1.55 m/s and 0.18짹12.01%, both p=NS) in patients treated with carvedilol. As compared with carvedilol, losartan treatment was associated with greater decrease in AIx (-5.03 versus 0.18%, p<0.05) but, the change of aortic PWV was not significantly different in losartan treatment. Both drugs significantly reduced central BPs to the similar degree. Conclusions: These data indicate that despite a less effect on aortic AIx, carvedilol had similar effects on central as well as peripheral BP and aortic stiffness as compared with losartan. Whether these features of carvedilol could translate into clinical outcomes different from atenolol in hypertension treatment awaits further investigation.