The inappropriate and unusual response of the immune system to the various types of antigens that the body has come into contact with is an allergy. Antigen is any substance that an organism recognizes as "foreign" and harmful and against which it produces antibodies. The creation of antibodies is our defence mechanism that allows us to protect ourselves from anything that the body considers dangerous. Allergens are antigens that cause allergic diseases and in the case of contact between the body and allergens, the body defends itself by producing protective antibodies which are specific to each allergen, so every allergy is specific. The reaction between a specific antibody and an allergen is called an allergic reaction. A food allergic reaction is an immune reaction of an organism to an individual food ingredient. Allergenic properties in foods are generally protein. The aim of this research is to examine the presence of food allergies in preschool children in two kindergartens: Kindergarten "Maza" in Valpovo and Kindergarten "Maslačak" in Belišće. A measurement instrument which was used in this research is a questionnaire. It was applied to a sample composed of the parents of 118 children aged 1 to 6 years. The questionnaire consists of 6 gender-related questions, age, allergy to certain nutritional foods, the doctor's knowledge of the allergy, and the use of therapy for an allergic reaction. The results of this questionnaire show that only 5 out of 118 preschool children are allergic to certain nutritional foods, which is 4,2%.