For more than 20 years hypertrophy regression has been in the focus of hypertension research. Many studies in animals have shown impressive reduction of left ventricular hypertrophy after medical treatment of hypertension. The most important result seems to be that hypertrophy can be almost completely reversed in young animals, whereas in older animals regression of left ventricular hypertrophy appears to be less complete. Hypertrophy regression in man seems much more difficult to prove. The direct correlation between left ventricular muscle mass and ECG changes has been disappointing in many studies. Echocardiography is able to show a comparatively good impression of left ventricular muscle mass and therefore can also demonstrate regression of left ventricular hypertrophy within its methodological limits. There is no doubt that today magnetic resonance imaging has by far the best imaging quality of all the clinical methods and is able to demonstrate both hypertrophy and its regression with incomparable accuracy. In the present clinical study hypertrophy regression has been demonstrated after 6 months of treatment with Carvedilol.