Background Cardiovascular events occur most frequently in the morning. We aimed to study the effects of monotherapy with the long-acting angiotensin II receptor blocker valsartan compared with the long-acting calcium antagonist amlodipine on ambulatory and morning blood pressure (BP). Methods We performed ambulatory BP monitoring before and after once-daily dose of valsartan (valsartan group, n = 38) and amlodipine (amlodipine group, n = 38) therapy in 76 hypertensive patients. To achieve the target BP of ≤140/90 mm Hg, valsartan was titrated from 40 mg/day to 160 mg/day (mean dose 124 mg/day) and amlodipine was titrated from 2.5 mg/day to 10 mg/day (mean dose 6.4 mg/day). Results Both drugs significantly reduced clinic and 24-h systolic BP (SBP) and diastolic BP (DBP) ( P < .002). However, the antihypertensive effect of amlodipine was superior to that of valsartan in clinical SBP (−26 mm Hg v −13 mm Hg, P = .001) and 24-h SBP (−14 mm Hg v −7 mm Hg, P = .008). In addition, morning SBP was significantly reduced by amlodipine from 156 to 142 mm Hg ( P < .001) but not by valsartan. Both agents reduced lowest night SBP to a similar extent (amlodipine 121 to 112 mm Hg, P < .001; valsartan 123 to 114 mm Hg, P < .002). Reduction in morning SBP surge (morning SBP minus lowest night SBP) was significantly greater in patients treated with amlodipine compared with those treated with valsartan (−6.1 mm Hg v +4.5 mm Hg, P < .02). Conclusions Amlodipine monotherapy was more effective than valsartan monotherapy in controlling 24-h ambulatory BP and morning BP in hypertensive patients.