Lung function tests were performed on 49 fire fighters of the city of New Haven. Their mean age was 36.4 years, with a mean of 11.7 years as fire fighters. The lung function tests were compared to a control group with a mean age of 33.4 years. There was no significant difference between the mean normal pulmonary function tests of the fire fighters and the control group. The results showed that in this group of fire fighters long-term occupational exposure was not associated with pulmonary function abnormalities.