Although left ventricular hypertrophy (LVH) is an adaptive response to the increased load imposed on the heart in patients with hypertension, it ultimately is itself a major risk factor for cardiovascular disease. The influence of LVH on left ventricular function and on the coronary circulation, and the occurrence of serious ventricular arrhythmias are the major mechanisms of this increased risk. There is no doubt that regression of LVH occurs, but there are clear differences in this respect among antihypertensive drugs: angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists produce the best response. Whether regression of LVH also causes an improvement in left ventricular function is unclear; various studies using the same drugs have yielded contradictory results. Furthermore, it has yet to be determined whether regression of LVH has a positive influence on the long-term prognosis in such patients; the results of the European Multicenter Study OvA will help in shedding more light on this important question.