Absenteeism is an important index that is related not only to health but also to direct daily activities. Itmay lead to a student's poor educational performance and overall reduction in educational quality.Particularly, diseases causing school absenteeism are important for environmental health of children's study.However only a few studies regarding the effects of air pollution on school absenteeism due to respiratorydisease have been reported. This study was performed to examine the effect of air pollution on absenteeismby respiratory disease, using school attendance reports from March 2002 to December 2004.In this study, we counted absenteeism numbers using school absenteeism data from the first to sixthgrade and classified absenteeism into illness-related, non-illness-related and respiratory disease-relatedillness absences. To this end, we used air pollution data (CO, NO2, PM10, and SO2) and temperature andrelative humidity data collected during the study period. Daily counts of absenteeism were analyzed byGeneralized Additive Model after the adjustment of several factors such as seasonal variation, day of theweek, and meteorological parameter confounders in a nonparametric approach.For each air pollutant, we analyzed illness-related absences, non-illness-related absences, and respiratory-illness related absences. Then, we considered both influenza and non-influenza related absenteeismtype. In illness-related absences analysis, absenteeism risks increased to 1.05(1.02-1.08) for CO and 1.06(1.02-1.10) for NO2 by each interquartile range change with adjustment for influenza. The risks forrespiratory-related absences of CO and NO2 increased to 1.05(1.02-1.08) and 1.04(1.01-1.08), respectivelyby each interquartile range change with adjustment for influenza. However, in the analysis ofnon-illness-related absences, there were no significant risks for the effect of all air pollution.This result shows that air pollution can affect respiratory-related absences and provides a basis fordeveloping environmental health policy against air pollution.