We evaluated the control condition of morning and evening home blood pressure (BP) and compared patients who had isolated uncontrolled morning hypertension and those who had sustained uncontrolled (morning and evening) hypertension using data from the Japan Home versus Office Blood Pressure Measurement Evaluation study. We evaluated 3303 treated hypertensive patients (mean age, 66.2+/-10.5 years; men, 44.7%) in Japan. We classified patients into controlled hypertension, isolated uncontrolled evening hypertension, isolated uncontrolled morning hypertension and sustained uncontrolled hypertension, based on the cutoff value of 135/85 mm Hg for both morning and evening home BP. Of the 3303 patients evaluated, 24.6% had isolated uncontrolled morning hypertension, and 42.0% had sustained uncontrolled hypertension. Factors associated with isolated uncontrolled morning hypertension included taking evening BP measurement after drinking alcohol or bathing. Factors associated with sustained uncontrolled hypertension were male gender, diabetes mellitus and renal disease. The regimen of antihypertensive medication was more complex in patients with uncontrolled morning hypertension than in controlled hypertension. Determinants of the difference between patients with isolated uncontrolled morning hypertension and those with sustained uncontrolled hypertension were diabetes mellitus, renal disease and lower prevalence in measuring evening BP after drinking alcohol or bathing. More than a half of the treated patients were classified into uncontrolled morning hypertension, which were associated with poorer prognosis. Classification of morning hypertensive patients into groups with or without evening hypertension may be useful for evaluating patients' total cardiovascular disease risk. Physicians should also consider evening BP measuring condition for adequate evaluation of evening BP values.