Evidence is abundant supporting the premise that left ventricular hypertrophy in hypertension is related primarily to the hemodynamic factor of the increased left ventricular afterload associated with the disease. However, evidence is rapidly accumulating that additional, nonhemodynamic factors are associated not only with development of left ventricular hypertrophy but also with its regression that is related to antihypertensive therapy. Included among these mechanisms are humoral factors, including a variety of participating (or inhibited) circulating pressor mechanisms (e.g., angiotensin, catecholamines); sexual factors; aging; racial factors; and the role of obesity and coexisting diseases. Precisely how each factor is translated into the biochemical events associated with development of hypertrophy remains to be clarified, as do the explanatory mechanisms of why certain depressor agents produce regression of ventricular hypertrophy, whereas other agents with more salutary hemodynamic effects do not. This paper discusses the rationale and evidence underlying each of these factors.