The purpose of this study was to evaluate the health hazards of firefighters after fighting a department store fire which lasted for 40 hours. Respiratory symptoms of 168 firefighters were collected and the pulmonary functions of 149 firefighters were measured by spirometer two days after fighting the fire and compared to 32 controls. The principal symptoms manifested by firefighters were burning eyes and mucous membrane irritation. Cross-sectional study of the pulmonary functions showed that FEV1.0, FEV1.0/FVC and the flow rates (MMF, FEF25%, and FEF75%) in smoking exposed firefighters were significantly lower than those in smoking controls. However, only FEV1.0 (%) was significantly lower in nonsmoking exposed firefighters than in nonsmoking controls. Both FVC and FEV1.0 showed a declining trend with the duration of fire fighting. This study provides further evidence that firefighters are exposed to irritants during fighting a fire. Exposure to the combustion products could lead to pulmonary function defects, especially in smoking firefighters.