OBJECTIVES: To evaluate the effect of low-level exposure of air pollutants on the respiratory tract of the children living near the petrochemical estate in Ulsan. METHODS: The study design was cross-sectional, and the study subjects consisted of 150 children(76 boys, 74 girls) living near the petrochemical estate and 100 children(53 boys, 47 girls) living in a suburban area. We investigated respiratory health using self-administered questionnaires(ATS-DLD-78), radiological examination, and pulmonary function test such as FVC and FEV1. RESULTS: There were higher prevalence rates of respiratory symptoms in the children living near the petrochemical estate than the children living in a suburban area. And the results of FVC and FEV1 of 11-years old children living near the petrochemical estate were lower than those of the children living in a suburban area. CONCLUSIONS: Chronic exposure of low-level air pollutants would affect respiratory health of the children. Therefore, further a longitudinal study of respiratory health will be needed for children living near the petrochemical estate in Ulsan.