Objectives: This study investigated lung function in workers exposed to dusts, fumes and noxious gases at small foundries. Methods: Lung function was measured in 148 male workers from 12 small foundries and 202 unexposed male workers. Pulmonary function tests performed included: forced vital capacity (FVC), forced expiratory volume in one second (FEV1), percent of FEV1/FVC (FEV1/FVC%), maximum mid-expiratory flow (MMEF), peak expiratory flow (PEF), and forced expiratory flow at 25, 50, and 75% of expired FVC (FEF25, 50, 75) Results: Mean values of all ventilatory indices except FEF25 of foundry workers were significantly lower than those of controls. Specifically, following stratification by smoking habits, all ventilatory indices except FEF25 of foundry workers were significantly lower than those of controls who smoked; however, there were no significant differences observed in any ventilatory indices between nonsmoking exposed workers and controls. The results of multiple linear regression analysis indicated work duration as a significant predictor of a decrease in FVC%. Conclusions: This research indicates that combined occupational exposure to dust, fumes, and gases in small foundries is associated with a reduction in lung function. Smoking may also contribute to respiratory abnormalities. These results suggested that foundry workers should be required to undergo periodic lung function tests and-in addition to not smoking, efficient use of personal protection equipment while at work is recommended.