Background and objective: To investigate the association between serological evidence of past infections with common respiratory pathogens and lung function in members of an isolated community of Aborigines from tropical coastal north-western Australia.Methods: FEV1 and FVC were assessed by dry bellows spirometer. Serum IgG titres to 11 common respiratory pathogens were assayed. Smoking history was assessed by questionnaire. Reciprocal positive IgG titres were taken as >= 10 for all pathogens with the exception of Legionella spp. (>= 40) and Burkholderia pseudomallei (>= 20). Linear regression analysis examined associations between titres and lung function after adjustment for age, height, gender and smoking, separately for adults (age > 17 years) and children.Results: An increased total number of positive IgG titres was significantly associated with reduced FEV1 (P = 0.01) and FEV1/FVC ratio (P = 0.01) suggesting the presence of airflow obstruction. This association was independent of age, gender, height, weight and smoking status.Conclusions: The burden of past respiratory infections may be an important determinant of airway function in this Aboriginal community.