Some mechanisms of the triglyceride-lowering effects of fibrates in patients with hypertriglyceridemia are reviewed. One main effect of the fibrates is the stimulation of lipoprotein lipase activities in plasma as well as in adipose tissue. According to this increase in the degradational activity VLDL catabolism is stimulated, as has been demonstrated for VLDL apo B and VLDL triglycerides. In addition, the composition of hypertriglyceridemic LDL is reverted towards normal. Furthermore, the increased degradation via the nonreceptor pathway is decreased by fibrate treatment, thus lowering the atherogenic potential of triglyceride-rich lipoproteins. But additionally the degree of postprandial hypertriglyceridemia is lowered by fibrates.