Out-of-office blood pressure (BP) monitoring, i.e., ambulatory and home blood BP monitoring, has better predict power of stroke than dose conventional BP. A large part of such evidence has been derived from a population-based prospective study in Japan (the Ohasama study). The Ohasama study has also revealed unique predictive power of theses monitoring. The predictive value of home BP increased progressively with the number of measurements. Even the initial-first home BP values (1 measurement) showed a significantly greater relation with stroke risk than conventional BP values (mean of 2 measurements). Home BP increased the predictive power of categorizations of guidelines compared to conventional BP. A disturbed nocturnal decline in BP determined by ambulatory BP is associated with cerebral infarction, whereas a large morning surge is associated with cerebral hemorrhage. Morning home hypertension, which is characterized specifically high home BP only in the morning might be a good predictor of stroke, particularly among individuals using anti-hypertensive medication. Since the Japan Home versus Office BP Measurement Evaluation (J-HOME) study demonstrated a poorly controlled condition of morning home BP in treated hypertensive patients, more aggressive treatment targeting morning home BP would be necessary to better prevent future stroke.