Introduction: Prenatal and postnatal smoke exposure is generally considered to be a strong risk factor for the development of respiratory symptoms and asthma, particularly in early life. The children exposed to environmental tobacco smoke had statistically significant higher prevalence of symptoms of allergic diseases.
 Objective:The aim of this study was to determine the influence of environmental tobacco smoke exposure on the prevalence of allergic diseases symptoms in children aged 6 to 15 years in Republic of Srpska.
 Methods: Our study was conducted as a cross-sectional study and included 3,000 children aged 6 to 15 years from 13 primary schools in Republic of Srpska. The allergic diseases symptoms and environmental tobacco smoke exposures were assessed by questionnaire, which was completed by the parents.
 Results: Maternal smoking during pregnancy was reported by 9,2% participants. Children were classified into two groups according to smoking status of householders: none (54,8%), and > 1 (45,2%). Children were not exposed to environmental tobacco smoke (62,9%) or they spent a short time in these rooms (< 1 hour 17,4%; 1-5 hours 14,4%; > 5 hours 5,3%) in our study. Children exposed to environmental tobacco smoke were reported a higher prevalence of wheezing (9,5%), allergic rhinitis (28,0%) and eczema (6,9%) than unexposed children (7,7%, 21,4% and 3,9%, respectively).
 Conclusion: In summary, our results support the need for public policy to protect children from environmental tobacco smoke exposure in their environment. Additional studies are needed to clarify the association betweenenvironmental tobacco smoke exposure and childhood allergic diseases.