Left ventricular hypertrophy (LVH) is a potent, independent predictor of cardiovascular events, particularly in hypertension, in which it dramatically increases the risk of stroke, coronary heart disease and heart failure. LVH is predominantly a surrogate marker for the effects of other risk factors integrated over time, but it may also contribute directly to cardiovascular disease through pathological changes in cardiac structure. The influence of blood pressure is central to LVH pathology, with 24-h blood pressure being more predictive of LVH than single clinic measurements. Blood pressure variation throughout the day is also emerging as an important correlate of LVH, and a strong association has been found between the early morning blood pressure rise and increased left ventricular mass. Antihypertensive treatment can reverse LVH, and preliminary studies suggest that this improves cardiovascular outcome and long-term prognosis. Most classes of antihypertensive agent show some effect on LVH regression, with the notable exceptions of minoxidil and hydralazine. However, many of the data regarding LVH regression come from small, poor-quality trials or from meta-analyses of these studies. In the few well-conducted studies that are available, certain classes of antihypertensive drugs are more effective than others. Those that target angiotensin II, such as the angiotensin II receptor blockers, appear to have a specific action on LVH that is independent of blood pressure reduction. Further high-quality studies are needed to define how LVH predicts cardiovascular risk, which agents are most effective at eliciting LVH regression and how such reversal can affect cardiovascular outcome.