Apoptosis is a mode of cell death in which intrinsic cellular mechanisms participate in the demise of the cell. The modulation of endothelial apoptosis may play a role in atherosclerosis, angiogenesis, vascular remodeling and other pathophysiological states. Control of cell death is mediated by the state of activation of a death pathway as well as by the levels of anti-apoptotic proteins. The final common pathway of many, if not all, triggers of apoptosis involves activation of cysteine proteases. The Bcl-2 family, in contrast, appears to play a major role in protection against apoptosis. The role of these mechanisms in modulating endothelial cell apoptosis under various conditions is discussed. J Atheroscler Thromb, 1996; 3 : 75-80.