The aim of this study was to compare the effect of morning and bedtime administration of valsartan/amlodipine combination therapy (80/5 mg) on nocturnal brachial and central blood pressure (BP) measured by ambulatory BP monitoring in patients with hypertension. This was a 16-week prospective, multicenter, randomized, open-label, crossover, noninferiority clinical trial. Patients underwent 24-hour ambulatory BP monitoring at randomization, at switching, and at the end of the study. Twenty-three patients (mean age, 68.0 years) were studied. The difference in nocturnal brachial systolic BP between the morning and bedtime administrations of combination valsartan/amlodipine was -3.2 mm Hg, and the two-sided 95% confidence interval ranged from -6.8 to 0.4 mm Hg. The difference in nocturnal central systolic BP was -4.0 mm Hg (95% confidence interval, -7.6 to -0.4 mm Hg). The upper limit of the 95% confidence interval was below the margin of 3.0 mm Hg in both nocturnal brachial and central systolic BP, confirming the noninferiority of morning administration to the bedtime administration of valsartan/amlodipine combination therapy.