Objective: A number of studies show an association between traffi c-related air pollution and adverse respiratory health effects in children. However, most evidence relates to the regions with low or moderate levels of ambient air pollution. The study was undertaken to assess the impact of traffi c-related air pollution on respiratory health status in children living in the area of high levels of industrial and municipal ambient air pollution. Materials and Methods: Analyses involved data obtained from cross-sectional study on respiratory health in children (N = 5733), conducted between 2003–2004 in Bytom, one of the largest cities of Silesian Metropolis (Poland). Exposure to traffic-related air pollution was assessed by means of geographic information system and expressed as several measures of potential exposure to traffic-related air pollution, involving residential distance to major road and traffic density in the residential area. Logistic regression was used to examin association between reported respiratory health and traffic measures. Results: Statistically signifi cant association was found between doctor-diagnosed asthma and residential proximity to traffic. Results of multivariate logistic regression (logOR; 95%CI) confi rmed the effect of living in an area of a city with high-traffic-density on childhood asthma: 1.60 (1.07–2.39). Similar effects were found in case of allergic rhinitis and rhinitis symptoms, but the observed associations were not statistically signifi cant. Conclusion: The study fi ndings suggest that even in an area with poor regional ambient air quality, adverse respiratory health outcomes are more frequent in children living in a proximity to the high vehicle traffic flow