The pathways of cellular synthesis, assembly, and secretion of lipoproteins followed by their subsequent intravascular metabolism and cellular uptake provide an efficient system for the transport of exogenous and endogenous lipids. The present report reviews the pathways of normal lipoprotein metabolism and the roles played by specific apoproteins, transfer proteins, enzymes, and cellular receptors in facilitating the transport of lipids in plasma, as well as in the regulation of cellular cholesterol homeostasis.