Non invasive blood pressure (NBP) measures are currently used in anesthesiology. The accuracy of this oscillometric technic has been tested with healthy patients, but not often with a wide pattern of pathology. The aim of this study is to point out the reliability of NBP during vascular surgery with patients suffering from arterial disease and atherosclerosis. It compares outcome with simultaneous catheter arterial blood pressure measurement (template technic). In this conditions, oscillometric method underestimates the systolic pressure value, and overestimates the diastolic one. The higher the level of arterial pressure is, the larger is the difference between this methods. It is clear that the automatic oscillometric technic is not so reliable if hypertension or atherosclerosis disease occurs. In order to improve this technic, automatic measures must take in account the degrees of arterial rigidity in its outcome.