In the past several years the importance of lipoprotein lipase (LPL) as a multifunctional protein, involved in several different aspects of lipid and lipoprotein metabolism, has become evident. Thus, in addition to its traditional role in mediating the initial hydrolysis of circulating plasma triglycerides, recent studies implicate LPL in the binding of lipoproteins to cell surfaces and receptors, as well as indicating a potential role for LPL in the pathogenesis of atherosclerosis. Enhanced understanding of LPL structure, function and mechanism of action has provided insights into new potential pathways by which defects in LPL function may result in the development of different hyperlipidemic disorders and/or atherosclerosis.