In the Japan Home versus Office Blood Pressure Measurement Evaluation (J-HOME) study, we examined the current situation with respect to the prescription of diuretics, including the prevalence of diuretic treatment and the dosages used for patients with essential hypertension in primary care settings. Of the 3,400 hypertensive patients included in the study, 315 (9.3%) patients (mean age: 66.9 ± 10.4 years; males: 43.5%) were prescribed diuretics. Compared with patients who were not using diuretics, those who were using diuretics were more obese and had more complications. The most commonly prescribed diuretic among the 331 prescriptions in the 315 diuretic users was trichlormethiazide (44%), followed by indapamide (15%) and spironolactone (14%). Among patients being treated with diuretics, monotherapy was used in only 5% of patients; in the majority of patients combination therapy including diuretics (95%) was used. Relatively low dosages of diuretics were generally used. There was a difference between the actual dosages prescribed and those recommended by the Japanese Society of Hypertension (JSH) guidelines or the product information approved in Japan. Compared with previous estimates of the prevalence of diuretic use in hypertensives in Japan (4.0-5.4%), the rate in the J-HOME study (9.3%) was higher. This may be attributable at least in part