The aim of this study was to evaluate the influence of verapamil SR 240 mg (V) and the combination amiloride 5 mg + hydrochlorothiazide 50 mg (AH) on diastolic dysfunction of hypertensive patients without left ventricular hypertrophy (LVH). Twenty-six hypertensive patients with diastolic dysfunction, normal systolic function and without LVH were included into a 2-week washout period and then randomised to a 6-month V or AH treatment. One blinded-to-treatment echocardiographist at baseline and at weeks 4, 12 and 24 assessed Doppler-echocardiography. Both V and AH, satisfactorily controlled blood pressure, but only V improved diastolic function shown by a tendency to reduce peak A and to increase peak E/A ratio, and by a significant reduction in deceleration time. After 24 weeks, V significantly reduced wall thickness in comparison with AH. These results need to be confirmed in a larger scale study.