In recent years assessment of baroreflex cardiovascular control in humans has received growing attention for two major reasons, i.e. 1) the availability of new techniques to evaluate this reflex function and 2) the possibility that a baroreflex alteration might play a role in the clinical evolution of cardiovascular diseases. This paper will briefly examine the alterations in baroreflex function in a variety of diseases affecting the circulation. In particular it will be focused on 1) the baroreflex control of heart rate and microneurographically measured muscle sympathetic nerve traffic in human hypertension, 2) the impairment of this reflex homeostatic function occurring in congestive heart failure of different clinical severity and finally 3) the transient alterations in baroreflex-heart rate control occurring in man in the acute post-myocardial infarction phase and during episodes of spontaneous myocardial ischemia.