The aim of this work is to review the role of the main risks factors in relation to cardiovascular diseases, and to evaluate the relative effectiveness of different preventive strategies. In the first part of the paper we summarize the historical background that allows us to understand the magnitude of this problem and its evolution. Secondly, we evaluate the significance of these strategies in the primary prevention of stroke and myocardial infarction, and how an intervention in one risk factor can have a greater significance for one of these events. But in any case, we must consider the whole benefit in each patient's health in our final evaluation of this intervention. Finally, we describe the strategies for hypertension and diabetes in order to reduce the incidence of end renal disease.