The World Health Organization recommends exclusive breast-feeding for the first six months of life. Breast milk remains the best source of nutrition for infants and mothers need to be motivated to continue as long as possible. However, when breast milk is not an option, health care professionals should be able to advise parents on the best alternative. Many different formulae are available for infants between 0-6 months. Although the main ingredients are strictly regulated by the European Union, formulae may differ in their protein and fat source, and in the addition of novel ingredients offering different benefits. Whey protein dominant infant formulae empty from the stomach in a similar way to breast milk, which is also high in this protein. Long chain polyunsaturated fatty acids impact on visual attention, cognitive behaviour and the immune system, whereas nucleotides decrease the risk of developing diarrhoea. The addition of specific prebiotics to infant formulae is relatively new, but the impact of these on the development of immunity in early childhood has been well researched. Health care professionals need to take these factors into account when advising parents on a suitable alternative to breast milk.