Although self-measured blood pressure (BP) at home (HBP) has become popular in clinical practice, little information is available regarding the proportion of diabetic patients with properly controlled HBP. We evaluated the status of HBP control in diabetic hypertensives. HBP control status was cross-sectionally evaluated among 3400 essential hypertensives taking antihypertensive treatment. Of these, 466 (14%) had diabetes. Physicians evaluated the subjects' HBP control as "poor", "fairly good", or "excellent" using a self-administered questionnaire. When the HBP threshold in diabetic patients was set tentatively at 130/80 mmHg or 135/85 mmHg, HBP was properly controlled in 18% or 30% of diabetic patients, respectively. The same trend was observed in office BP. The average number of drugs prescribed for diabetic patients was 2.0 drugs. In the majority of diabetic patients with uncontrolled BP, the BP control status in two-thirds of those was evaluated as "excellent" or "fairly good" by their physicians. In Japan, HBP and office BP were not adequately controlled in most diabetic hypertensives. The main reason for this would appear to be a lack of intensive treatment and a lack of recognition by physicians that their patients' BP was insufficiently controlled.