Burn inhalation has negative effects on pulmonary function and may result in whole airway damage. The consequences of a methane explosion are thermal injury of the respiratory tract, shock wave, and carbon monoxide intoxication. The aim of this study was to determine changes in the pulmonary function tests (PFTs) after six years of follow-up in miners who survived a methane explosion. Two groups were examined: 41 miners who fell victims to a methane explosion and had a documented thermal injury of the respiratory tract and 25 healthy miners who served as controls. Pulmonary function studies were repeated after six months and six years from the time of injury in 33 study subjects and at the same time intervals in 16 control subjects. The study included static and dynamic lung volumes and diffusing capacity for carbon monoxide (DLCO). The mean values of PFTs were within normal ranges in both groups examined six months and six years after the injury. A significant decrease in DLCO was observed in the victims (98.4% vs. 85.4%), but not in the control group, after a six years' observation. The decrease may be one of the reasons for a breathing discomfort emerging in these patients. In the control subjects we observed a significant decrease in FEV1 (96.4% vs. 83.4%)--over a six years' period. This finding is due likely to smoking and heavy pollution of the working environment.