Aim: to assess whether indoor toluene may affect respiratory health in schoolchildren. Methods: Health status and related risk factors were assessed through questionnaire in 628 children (mean age 10yrs) of five European countries: Sweden, Norway, Denmark, France, Italy (EU-funded HESE Study, Health Effects of School Environment). Measurements of pollutants were performed in 46 classrooms. Toluene was measured by active sampling using charcoal tubes. Results: The levels of toluene were relatively low: median concentration was 4.57, significantly higher in France (12.12) than in the other four countries (range: 2.82 in Sweden to 5.09 µg/m3 in Italy). Prevalence rates of dry cough at night and wheeze were respectively 35% (range: 17 in Sweden to 48% in Italy) and 13% (range: 10% in Northern countries to 18% in France). Multiple logistic regression, accounting for centre, gender, age, presence of asthma, passive smoking at home, other indoor pollutants (PM10, CO2, viable moulds) indicated toluene to be associated with higher risk of dry cough (OR 4.37, 95%CI 2.19-8.75 per 1 µg/m3 increment) and wheeze (OR 3.24, 1.25-8.45). These associations were significant after further accounting for the fixed effect of the classroom. Conclusion: Although toluene levels in classrooms were relatively low, long-term exposure seems to be a risk factor for respiratory health of schoolchildren.