The hypothesis that the bedtime dosing of angiotensin receptor blocker (ARB) is superior to morning dose in improving baroreflex sensitivity (BRS) and urinary albumin/creatinine ratio (UACR) was tested in this study. Baroreflex sensitivity was measured at baseline and at 6th month (N = 109) and was found to increase in the bedtime-dose group (P = .004), but not in the morning-dose group. The correlations between the change in BRS and the change in UACR were insignificant in the morning-dose group (r = 0.17, P = .26), but were significant in the bedtime-dose group (r = -0.29, P = .04). In conclusion, the improvement of BRS could be one of the mechanisms by which bedtime dosing of ARB confers renal protection.