Subjects in the study were 158 female wool textile workers and 87 control non-exposed workers. Respiratory symptoms were assessed by means of a questionnaire. Ventilatory capacity was measured in wool workers by recording maximum expiratory flow-volume (MEFV) curves on Monday before and after the work shift. Forced vital capacity (FVC), one-second forced expiratory volume (FEV1) and flow rates at 50% and the last 25% of the vital capacity (FEF50, FEF25) were measured on MEFV curves. Significantly higher prevalences of all chronic respiratory symptoms were recorded in exposed than in control workers (P < 0.01). Exposure to wool dust caused significant across shift reductions of ventilatory capacity varying from 2.0 to 9.1%. Those reductions were similar in textile workers exposed to wool for more than 10 years showed similar across shift reductions of ventilatory capacity tests as those with shorter exposure. Smokers and non-smokers had similar acute and chronic lung function changes. In a larger number of wool workers FEF50 and FEF25 were below 70% of predicted normal values. Bronchoprovocation testing with wool dust extract did not demonstrate correlation with respiratory impairment. Our data suggest that dust exposure in wool textile mills may be associated with the development of chronic respiratory symptoms and impaired lung function.