Non-invasive ambulatory blood pressure monitoring has proved to be very useful in investigating hypertensive patients. So far, almost everything known about this technique is based on studies performed in specialized centers. We summarize here the results of two trials in which private physicians used ambulatory blood pressure monitoring to assess the efficacy of antihypertensive drugs. The results found in this clinical setting were very similar to those observed previously in specialized clinics. In the individual patient, the level of ambulatory recorded pressure could not be predicted from blood pressure readings taken at the doctor's office. Furthermore, the blood pressure response to antihypertensive therapy was more reproducible when evaluated by ambulatory blood pressure monitoring than by the doctor. It appears, therefore, that non-invasive ambulatory blood pressure monitoring is also useful in everyday practice for the management of hypertensive patients.