Background. Epidemiological studies point out that air pollution in the cities was a major risk for health of the exposed population. In particular, the effects of air pollutants were adverse to the respiratory tract. In Niš and Niška Banja, the concentrations of pollutants were mainly below the threshold values. However, according to the literature, even these concentrations could exert negative effects, especially the health of the most sensitive group, such as the preschool children. The aim of our study was to evaluate the effects of the current levels of air pollutants in the city of Niš on respiratory symptoms and diseases. Methods. A pilot, cohort, retrospective study included 1 385 children of 1-5 years of age from the zones with statistically significant concentrations of air pollutants, in the period after the birth of the children. The prevalence of respiratory symptoms and diseases was determined on the basis of a modified WHO standard questionnaire completed by the parents. Results. It was revealed that in the more polluted of the studied zones, the prevalence of some respiratory symptoms (cough with cold and phlegm), and the lower respiratory tract diseases was significantly higher. Conclusion. The results of our study showed that the current concentrations of air pollutants in Niš and Niška Banja could represent the important etiological factor for the development of respiratory symptoms and diseases. Our study showed that in the children of up to 5 years of age, the frequency of respiratory symptoms and diseases was significantly higher in more polluted than in less polluted environments.