The purpose of the study was to assess the effect of indoor air pollution resulting from the use of gas stoves for cooking on women more than 65 years old, who may be more susceptible than younger women to the harmful effects of pollutants. A total of 1,544 women living in Cracow took part in a survey. The data were collected to standardized interviews dealing with respiratory symptoms (coughing, phlegm production, dyspnea on exertion), chronic chest diseases diagnosed by a doctor, active and passive smoking, educational level, type of cooking fuel used, and average time spent daily in cooking. Lung function was tested with a spirometer. Comparison of the prevalence of respiratory symptoms by daily duration of cooking of smokers with that of never-smokers showed more symptoms in smokers even in the low-exposure category. In multivariate analysis, the effects of duration of cooking with gas on asthma for the highest exposure category in terms of odds ratios (ORs) were 2.8 for the never-smokers and 2.4 for the smokers; however, passive smoking had no significant effect. As regards dyspnea on exertion, both gas cooking and passive smoking had significant effects in never-smokers (OR for gas cooking 7.2, for passive smoking 2.2). The OR for dyspnea due to cooking with gas in smokers was 3.1. Mean FVC and FEV&inf1; levels were not decreased among passive smokers or those who were subject to high levels of gas-cooking exposure.