Arterial distensibility reflects mechanical properties of the arterial wall and have, thus a clearcut clinical relevance. This because an arterial distensibility reduction is associated with an increased pulse pressure, an increased cardiac work and a reduced diastolic vital organ perfusion. In recent years it has been demonstrated that arterial distensibility is reduced in marked and mild hypercholesterolemia, in a manner independent from arterial blood pressure values. Arterial mechanical properties are also impaired in heart failure, this leading to a further cardiac damage. This important vascular properties however, can be improved by appropriate treatment, while the time needed for that can be extremely long.