We evaluated the modifications induced by chronic treatment with an alpha 1-adrenolytic hybrid drug, urapidil, on the hemodynamic parameters in peripheral artery and left ventricle diastolic function. Fifteen mild to moderate essential hypertensive patients (13 men, 2 women; mean age 42 years, range 32-54 years) received urapidil (60 mg b.i.d.) for 6 months. Peripheral hemodynamic and cardiac parameters were evaluated by duplex scanner, coupled with a plethysmographic method, basally (T0) and after 6 weeks' (T1) and 6 months' treatment (T2). Mean blood pressure (BP) showed a reduction after 6 weeks of -9.07 mm Hg (confidence intervals [CI] 95%: -9.21; -8.92; P < 0.01), which was maintained after 6 months (-8.21 mm Hg, CI 95%: -8.97; -7.43; P < 0.01), while no significant change was seen in heart rate. Compliance showed highly significant changes after both 6 weeks (+1.073 dyn-1.cm4.10(-7), 95% CI: +0.965; +1.181, P < 0.001) and 6 months (+0.933 dyn-1.cm4. 10(-7), 95% CI: +0.903; +0.963, P < 0.001), as well as characteristic impedance (T1:-16.689 dyn.s.cm-5/10(2), 95% CI: -16.914; -16.463 P < 0.001; T2: -15.98 dyn.s.cm-5. 10(2), 95% CI: -18.186; -13.784; P < 0.001) and forearm resistances (T1: -26.153 mm Hg.ml-1.s, 95% CI: -34.553; -17.753, P < 0.01; T2: -43.587 mm Hg.ml-1.s, 95% CI: -52.711; -34.464, P < 0.01). Similarly, we have recorded a similar change in left ventricular end-diastolic posterior wall thickness (T1: -1.067 mm, 95% CI: -1.099; -1.035, P < 0.01; T2: -2.866 mm, 95% CI: -3.044; -2.688, P < 0.01), end-diastolic interventricular septum thickness (T1: -0.921 mm, 95% CI: -1.511; -0.289, P < 0.05; T2: -2.711 mm, 95% CI: -3.211; -2.199, P < 0.01), end-diastolic volume (T1: +6.4 ml, 95% CI: +6.343; +6.456, P < 0.01; T2: +19.867 ml, 95% CI: +18.564; +21.170, P < 0.01), and mass/volume index (T1: -0.11, 95% CI: -0.118; -0.101, P < 0.01; T2: -0.218, 95% CI: -0.221; -0.217, P < 0.01). Changes in arterial compliance have shown a statistically significant correlation with changes in mass/volume index (r = -0.468; P < 0.03), end diastolic volume (r = 0.501; P < 0.02), as well as left ventricle rapid filling phase (r = 0.426; P < 0.05) and left ventricle end diastolic posterior wall thickness (r = -0.478, P < 0.03). Our results suggest that the antihypertensive efficacy of urapidil coupled with the restoration of the dumping function of the large arteries, and the reduced activation of reflex sympathetic activation, may play a considerable role among the mechanisms allowing the regression of the functional modifications affecting the left ventricular diastole.