The aging process and the elevation of arterial blood pressure (BP) have synergistic effects on the modifications of the arterial system. The effects of the treatment on these modifications are unknown. Our objective was to study the consequences of anti-hypertensive treatment on the geometry and function of the arteries in men over 70 years old. In 89 men aged 74 +/- 2 years, we measured internal diameter and intima-media thickness (IMT) of carotid and radial arteries using high resolution echography (WALL TRACK SYSTEM and NIUS-02), and carotid-femoral pulse wave velocity (PWV) by COMPLIOR. The BP was measured in supine position by Dinamap. In 28 subjects the BP was more than 140/90 mmHg (poor controlled hypertensives-HTpc); in the subjects where BP < 140/90 mmHg, 44 were normotensives (NT) without treatment and 17 were well controlled hypertensives (HTwc) on use of at least one antihypertensive. [table: see text] The PWV was increased in HTpc (20.1 m/s) in comparison with NT (14.6 m/s) and HTwc (16.1 m/s) (p < 0.05). The operational distensibility of radial artery was similar in the three groups. In conclusion, in elderly men aged more than 70 years, the anti-hypertensive treatment can normalize the functional properties and the geometry of muscular and elastic arteries. These results indicate that the arterial modifications observed in elderly hypertensives are consequence of the high blood pressure per se and not only consequent the modifications due to the aging.