Twenty seven healthy individuals were divided randomly into three groups. The first group of nine subjects received only a routine bronchoscopic examination. The second group of nine subjects was examined with the bronchoscope followed by bronchoalveolar lavage (BAL) with 200 ml of 25 degrees C normal saline solution. The third group of nine subjects received a bronchoscopic examination followed by BAL, but with 200 ml of 37 degrees C normal saline solution. Examination in all groups included arterial blood gas (ABG) analysis and pulmonary function test (PFT), both pre- and post-procedure. In group 1 there was no statistical difference in the pulmonary function test result after routine bronchoscopic examination except for decrease in PaO2. The results in group 2 showed a statistical difference in both ABG and PFT data, especially PaO2, FEF 200-1200, FEF25%-75%, FEF25%, FEF50%, and FEF75%. In group 3, there was a significant decrease of PaO2 and no significant difference in PFT before and after BAL. From these data we conclude that BAL is a safe examination. However, the administration BAL fluid (BALF) with 25 degrees C normal saline solution can affect the results of the PFT significantly. Much of this adverse reaction can be minimized by using body temperature (37 degrees C) saline solution. At 37 degrees C, the ABG data showed a decrease in PaO2, but pulmonary function was not affected significantly.