The load of the heart in hypertension is related not only to increased peripheral vascular resistance but also to decreased aortic compliance. From non-invasive clinical studies involving determinations of pulse wave velocity and systolic-diastolic variations of aortic arch diameter, it can be shown that decreased aortic compliance is strongly related to increased cardiac mass. The correlation is observed even after adjustment for the level of blood pressure. It is suggested that decreased aortic compliance in hypertension causes a disproportionate increase in systolic pressure and end-systolic stress, thus contributing to promote cardiac hypertrophy with possible consequences for epidemiology, clinical investigation and treatment.