Drug treatment of high blood pressure had important improvements is the last few decades, that allowed an efficiente control of hypertension, avoiding or stabilysing cardiovascular consequences. Non pharmacological management is always important; however most hypertensive patients need also drug treatment that is unavoiable in severe and in most cases of moderate hypertension. Borderline hypertension involves difficult decisions. Quantitative diagnosis of high blood pressure has been based on casual measurement. Non invasive ambulatory blood pressure measurement gives access to much more valures over the whole day and night periods, and has been an important tool for clinical research. However it implicates a correct assessment of the device's accuracy and calibration, and also a correct statistical treatment of the huge range of values obtained. Blood pressure control over the 24 hours is probably obtained with some long acting drugs. So, calcium antagonista are reviewed, exemplofying with slow release diltiazem. It has been prescribed twicely a day, and more recently once a day, what is considered by some authors quite adequate on the point of view of pharmacocinetics and pharmacodynamics. So the benefits depending on patient's compliance and the possible obliteration of hypertensive spikes may be important. There is perhaps, in the overall, reduction of health care costs, in what concerns hypertension.