To evaluate the effects of antihypertensive agents on the circadian blood pressure (BP) of patients with previous brain infarction, the ambulatory BP was measured non-invasively for 24 h before and after administration of antihypertensive agents. One hundred milligrams of acebutolol twice daily (n = 15) is effective in lowering the BP during the daytime, but has little effect during the night and the morning. Twenty milligrams of slow-release nifedipine twice daily (n = 14) produced a consistent reduction in the BP over the entire 24-h period and effectively blunted the rise in BP in the morning. Captopril (12.5 mg) twice daily (n = 15) produced a mild reduction in BP with little change in the circadian pattern. The slow-release nifedipine group had the greatest decrease in mean systolic and diastolic BP. The heart rate significantly increased after administration of slow-release nifedipine and decreased after administration of acebutolol. To reduce stroke recurrence, we should consider the effects of antihypertensive agents on circadian BP in hypertensive patients with previous brain infarction.