Breast milk is essential for the infant and his/her immune system for growth and development. Breast milk has a perfect combination of proteins, fatty acids, carbohydrates, which makes it the best source of nutrition for infants. The antibodies, cytokines, various enzymes, macromolecules and different viable cells in breast milk are extremely necessary for the newborn in fight against infectious diseases. At the same time, the microbes found in healthy breast milk largely participate in the shaping of the newborn’s immune system. Infants will highly benefit from breastfeeding for at least first six months of life. Thereafter, whenever it is feasible, mothers should feel themselves encouraged to breastfeed their child up to two years of age or beyond during which time he/she receives nutritionally adequate complementary foods.