Summary: In Poland, cow's milk protein allergy affects approximately 1% of children younger than 2 years of age and is the most common food allergy in young children. Treatment is based on a maternal dairy-free diet in breast-fed infants, as well as an extensively hydrolyzed formula and/or amino-acid formula in formula-fed infants. The article presents cases of severe cow’s milk protein allergy requiring the use of amino-acid formula.