We have studied ambulatory hypertensive patients by means of a survey protocol, in order to observe the possible causes of inadequate control. In 8% of patients, hygienic and dietetic measures were applied, specially low-salt diet and weight loss. This percentage is very low compared to that reported by other authors. A 67% of our patients received monotherapy, being diuretics the most frequently used drug. A 71% of patients fulfilled (correctly) the prescribed drug treatment, independently of its complexity and the arterial hypertension evolution time. The degree of good treatment fulfillment, in relation to the scarce fulfillment of hygienic and dietetic measures, make us believe that in our environment patients trust drugs effects more than that of the diet. We believe that this is due, in part, to the fact that health professionals do not insist sufficiently in its fulfillment. Patient follow-up was satisfactory in only 46% of them, which conditioned the fact that hypertension control was efficient in only 39% of total. We suggest the importance of treatment and control programs in primary assistance given the better results claimed by other authors who worked with patients following protocols. Only thus the Internal Medicine Departments could be relieved from problems derived from these patients.