Summary: There is no doubt that breastfeeding is the optimal way of feeding infants. In the case of inability of natural feeding, we introduce modified milk formula replacing motherís milk in the childís diet. They are often the only source of nutrition for growing and developing infants. Manufacturers constantly modify their products to make it resembles motherís milk. Standard infant formulas, which are the basic substitutes for human milk, are based on cowís milk. There is a line of infant formulas with a modified composition, which allows effective prevention and treatment of diseases, which are based on a wrong reaction to a specific component. These products are modified by changing the lactose content, addition of probiotics or rice starch and partially hydrolyzed protein. There are also specialized recipes used in special cases, such as prematurity, gastrointestinal disorders, allergies, disorders of fat metabolism and renal failure. Infants fed with special milk replacer formulas should be under the constant care of a physician. Milk replacers are available in several forms enabling convenient preparation tailored to the needs of parents. On the market you will find preparations in ready-to-eat form, liquid concentrate and powder. However, each of them has its own advantages and disadvantages.