Abstract Rationale Outdoor nitrogen dioxide (NO 2) is associated with reduced respiratory health. This could be due to a unique biological effect of this gaseous pollutant or because it serves as a surrogate of fine particles from incineration sources. Cooking with gas in small kitchens produces high concentrations of gaseous irritants (mainly nitrogen dioxide), but not fine particles. Objectives To study the relative impact of cooking with gas on lung function parameters in a cross sectional study of school children. Methods Nearly all elementary school children (2898 children aged 6–10 years) living in the city of Linz (capital of Upper Austria) underwent lung function testing. In a questionnaire administered simultaneously to their parents, information on household conditions including cooking and tobacco smoke exposure was collected. Impact of cooking with gas on lung function controlling for various confounders was analyzed using loglinear multiple regression. Results Gas cooking reduced lung function parameters ranging from 1.1% (not significant) for MEF 25 up to 3.4% ( p = 0.01 ) for peak expiratory flow (PEF). Conclusions Gas stoves can have an adverse impact on children's respiratory health. Parents and caretakers should be advised to insure good ventilation while and after cooking, especially in small and poorly ventilated rooms. This study adds to the growing evidence that gaseous pollutants from incineration sources affect respiratory health directly.