Since lipids are insoluble in water, they are transported in plasma by lipoproteins composed of several classes of lipids (including cholesterol, triglycerides, and phospholipids) and proteins named apolipoproteins. Each class of lipoprotein has a specific function in lipids metabolism. Chylomicrons transport dietary triglycerides and cholesterol from the intestine to peripheral tissues, Very Low Density Lipoproteins (VLDL), are synthetized by the liver to export triglycerides, Low-Density Lipoproteins (LDL) represent a final stage in the catabolism of Very low density lipoproteins and High Density Lipoproteins (HDL) are involved in reverse cholesterol transport. The role of lipoproteins receptors, enzymes, apolipoproteins and transfer proteins is also discussed.