Background and Objectives: Due to industrialization and ineffective pollution control measures indoor air pollution is major health problem in developing countries. Flour dust occurs across the range of food industries, its exposure induce acute or chronic respiratory problems. This study is aimed to compare the effect of flour dust on the lung functions of male flour mill workers with healthy subjects not exposed to flour dust. Method: We evaluated 30 flour meal workers in the age group of 20-50 years.30age and sex matched healthy subjects non exposed to dust were taken as controls. The PFT’s were carried out with a computerized spirometer “Med-Spiror”. The various data was collected, compiled, statistically analyzed and valid conclusions were drawn. Results : The present study results showed a significant decrease in the mean values of FVC (Forced vital capcity), FEV1(Forced expiratory volume in first second), FEV1%(FEV1 /FVC percentage) , FEF25-75%(Mean forced expiratory flow during the middle of FVC), PEFR(Peak Expiratory flow rate) and MVV(Maximum voluntary ventilation) in flour mills workers as compared to controls.Conclusion: Flour dust causes chronic bronchial irritation which is responsible for the obstructive as well as restrictive type of pulmonary impairment of lung functions.