Background. To study the prevalence of symptoms of allergic diseases among school students of the Grodno region (Republic of Belarus). Methods. Researches conducted a questioning method by means of the Russian version of the standardized «International Study of Asthma and Allergy in Childhood» program (ISAAC). Results. Results of questioning of 1787 schoolchildren showed that the wheezing, within the last 12 months was registered in 9,3% of children of the first classes (DI: 7,5-11,5%) and in 9,1% of children of the eighth classes (DI: 7,5-11%), rhinitis symptoms without cold or flu - in 29,7% of children of the first classes (DI: 26,7-32,85%) and in 47,2% of children of the eighth classes (DI: 44-50%), symptoms of atopic dermatitis - in 8,2% of children of the first classes (DI: 6,6-10%) and in 1,9% of children of the eighth classes (DI: 1-2,97%). Frequency of clinically verified diagnosis of bronchial asthma at schoolchildren at the age of 6-7 y.o. and at the age of 13-14 y.o. was 3,9% (DI: 3-4,9%), allergic rhinitis - 5,6% (DI: 4,6-6,8%), atopic dermatitis - 6,2% (DI: 5,2-7%). Conclusion. Results of the study confirm the need of carrying out further epidemiological researches for the purpose of earlier identification of patients with allergic diseases.