Summary: Cow's milk protein allergy (CMPA) is one of the most important allergic diseases in infants. The crucial method of CMPA treatment is the use of an elimination diet, i.e. special modified formulas. The need for an elimination diet is inevitably associated with the risk of nutritional deficiencies. The article presents the current knowledge on the epidemiology, clinical picture and principles of CMPA treatment. The risk factors of nutritional deficiencies in children with CMPA as well as the principles of diagnostic and therapeutic procedures were underlined.