Lipoprotein lipase (LPL) is a rate-limiting enzyme for the hydrolysis of triglycerides. Recently new insights into non-enzymatic functions have emerged. Complete lipoprotein lipase deficiency associated with chylomicronemia is an uncommon (1/10(6) in the general population) autosomal recessive disorder caused by many different lipoprotein lipase gene mutations and is characterized by high fasting plasma triglyceride levels, that can be complicated with acute pancreatitis. To date, about sixty gene mutations have been described throughout the world. Conversely to the homozygous state, the heterozygous state predisposes to a lipid profile that may be atherogenic evenly frequent (approximately 1/500) in the general population. These new clinical and biological insights reinforce the multifunctional role of lipoprotein lipase.