This study evaluates 33 patients suffering from mild-moderate arterial hypertension (systolic blood pressure over 160 mmHg; diastolic blood pressure over 95 mmHg) and with concomitant indications of concentric left ventricular hypertrophy at echocardiography. Twenty patients completed the trial according to the criteria established in the protocol and were found suitable for evaluation of the results at the end of the study. Ten patients were treated with 40 mg of nifedipine retard tablets, administered twice (1 x 20 mg tablet twice daily) and 10 patients were treated with a single administration of 20 mg quinapril (1 x 20 mg tablet per day). Total follow-up was performed for one year (variability 12-14 months) with evaluation of the pressure response at 1-3-6-12 months and clinical evaluation and echocardiographic control for comparison with the baseline at the end of the study. The left ventricular mass values measured at the end of the study presented a statistically significant reduction (p < 0.001) with respect to the baseline in both groups. In the patients treated with quinapril the percentage regression of left ventricular hypertrophy was 19.39%, and slightly higher (19.5%) in the patients treated with nifedipine. Finally, although the series is perhaps too limited to draw conclusions, the finding that the indicators of diastolic filling of the left ventricle improved, and, in particular, were correlated with an increase in the speed of the first fast filling phase, and thus that there was a partial improvement in left ventricular compliance, is important.