Morning hypertension is an independent risk factor for cardiovascular diseases, particularly stroke. However, the optimal time at which to take antihypertensive medication to treat morning hypertension remains unclear. We prospectively enrolled elderly patients (over 65 years old) with morning hypertension who had suffered an ischemic stroke (or strokes). Additional treatments (one of six arms) were randomly administered for 10 weeks in the morning, in the evening or at bedtime (n=15 for each time point/medication). The patients measured their blood pressure and heart rate at home for 14 days prior to the intervention and for the final 14 days, and recorded the data in a blood pressure diary. The patients' urinary albumin/creatinine ratios were evaluated before and after the 10-week intervention. A total of 270 patients were enrolled in this study (mean age: 75.6±5.8 years; female/male ratio: 125/145). Their morning and evening systolic blood pressures were significantly decreased after following any of the study medication dosing schedules (P<0.001). However, the reductions in the differences between the morning and evening systolic blood pressures were significant only when the medication was taken in the evening or at bedtime (P<0.001 with repeated measures analysis of variance). Furthermore, the recovery rate from morning hypertension was also higher when the medication was taken in the evening (40.0%) or at bedtime (45.6%), rather than in the morning (22.2%; P=0.003 with the χ(2)-test). Antihypertensive medication taken in the evening or at bedtime is the most effective in treating morning hypertension when the patient adheres to the medication regimen.