Background. Lyme disease – natural and nucleus inoculable disease caused by Borrelia(Borreliaburgdorferi), catching by clips and becomes apparent by inoculable ring-shaped erythema, fever, affection of central and peripheral neural system, heart and big joints.This disease occurs on the territory of Eurasia of forest and forest-steppe zones.The western part of Ukraine including Ternopil oblast is endemic zone of Lyme borreliosis. It is located in an area with the forest landscapes (the total area of forest area is 199.3 thousand ha of broad leaves and mixed-broad leaves trees pecies); Areas Ixodestick-borneborreliosis found in 57 localities 14 districts of the region and the city of Ternopil. Objective. To detect the prevalence of Lyme borreliosis among children of Ternopil region, Western Ukraine.This study is a part of the Ukrainian-Polish project “Investigation of epidemiology, pathogenesis, clinics and prophylaxis of borreliosis”.Methods.These studies covered 200 children, with middle age (10,02±4,29).There were patients from Ternopil regional children hospital with different somatic pathology.The croup of the examined patients comprised 44% girls and 56% boys. 32 of the tested group, has answered the questions of compatible international questionnaire. Results.The majority of the examined children (47,0%) reported tick attack during their life. There were children from the early school age. On seasonal, tick bites the highest rate was during May-July, where in May – 6%, in June – 38%, in July – 31%, in August – 3%, in September – 6% accordingly.The most disturbing is that 6 % of examined patients do not remember the month of the tick bite generally. Conclusions.The presented study show, that children’s from Ternopil region (endemic zone of Lyme borreliosis),are exposed to tick bite, more often in May-July of the year.The elaboration of educational and prophylactic standards among the tested group is needed, more active during the winter months.