Technical Abstract: More than 90% of women in developing countries and 50 to 90% of women in industrialized countries now initiate breast-feeding, a marked improvement from 25 y ago. The duration of breast-feeding has lengthened, but fewer than 35% of infants worldwide are still exclusively breast-fed at 4 mo of age. Considerable progress has also been made in combating infant malnutrition. In 1980, 47% of under-5-y-old children in developing countries were stunted. This percentage declined to 29% in 2005. Major advances in formula use and composition include the introduction of formulas tailored to the perceived needs of low-birth-weight infants and the development of fortifiers to overcome the nutritional deficits of human milk for the preterm infant. More recently, postdischarge formulas were introduced and are now being used widely, often in combination with breast-feeding. Formulas for term infants also have undergone a number of changes in the past 25 y to better reproduce the composition of human milk and/or the response of the breast-fed infant. The use of whey-predominant rather than casein-predominant formulas has increased, as has the use of iron-fortified formulas. Cow's milk is introduced into the infant's diet much later than 25 y ago. Despite the progress that has been made in promoting breast-feeding and in the quality of infant formulas, further improvements in the duration of breast-feeding and in the composition of infant formulas are needed.