The plasma lipoproteins provide the body with a transport system for the otherwise insoluble lipids. All lipids except for free fatty acids and lysolecithin, circulate in plasma from their site of origin to their site of utilization in association with these lipid-protein complexes, the lipoproteins. In healthy humans, more than 100 g of triglycerides, phospholipids and cholesterol are transported each day in lipoproteins; under certain pathological conditions, the human plasma lipoprotein system may contain more than 500 g of lipids. The aim of the present review is to define the various lipoproteins, describe their routes of metabolism and identify the possible mechanisms by which drugs may affect lipoprotein metabolism.