OBJECTIVE Flour dust occurs across the range of food industries; its exposure may induce acute or chronic respiratory ailments. The objective of the study was to assess the effects of flour dust on the lung function. METHODS The lung function was studied in forty-six male flour mill workers and a similar number of male control subjects; all participants were non-smokers with the age range from 18 to 65 years. The subjects were matched for age, height, weight and socioeconomic status. The pulmonary function test was performed by using an electronic spirometer (Compact Vitalograph, UK) and results were compared by a paired t-test. RESULTS Significant reduction in the overall mean values of FVC, FEV1, PEF, and MW were observed in wheat flour mill workers relative to their matched controls. CONCLUSIONS Based on the results of the present study, we conclude that the flour mill workers in Pakistan, like grain workers elsewhere, are at an increased risk of developing occupationally related pulmonary function impairments. The results suggest that there is an urgent need to improve dust control measures and the health status of flour mill workers.