Dietary lipids represent a major source of energy for infants and toddlers and are also of qualitative and functional importance for their health. This chapter will provide a focused overview of several characteristics of breast milk lipids in this context. On a molecular scale, the fatty acid profile of breast milk present an adequate amount and profile of n-3 and n-6 polyunsaturated fatty acids (PUFA) associated with a specific molecular structure of the triacylglycerols for an optimum digestion and absorption. To a lower extent, breast milk contains polar lipids including sphingolipids and sterols including cholesterol and phytosterols that can present bioactive effects. On a supramolecular scale, lipids are organized in breast milk in the form of milk fat globules (MFGs) surrounded by a trilayered biological membrane, the milk fat globule membrane. Therefore, the breast MFG size distribution and interface composition are dramatically different from emulsion droplets encountered in infant formula. These properties have been shown to impact on lipid digestion and absorption by the infant. Finally, infant formula contain lipid peroxidation products from the PUFA that are present to meet infant needs. In contrast, breast milk PUFA appear to be protected from oxidation even after several days of storage. Altogether, the specific composition of breast milk lipids, their organization as MFGs and their resistance to oxidation can provide several beneficial nutritional impacts for the infant compared with infant formula.