The purpose of the present study was to determine the structural integrity of red blood cells in coal miners by assessing the concentration of malondialdehyde and the activities of superoxide dismutase and, Na+, K+ -ATPase in erythrocytes. Occupational exposure to coal mine dust can result in a wide range of lung diseases, which include pneumoconiosis, bronchitis, and emphysema. Pathophysiological mechanisms of the diseases are not fully understood; however, cytotoxicity is related to reactive oxygen substances which are produced by coal dust. The study population consisted of 40 coal workers previously known not to have any pulmonary disease and 34 healthy subjects who were randomly selected from the population register or recruited from the hospital staff. The activities of Na+, K+ -ATPase in the erythrocyte membrane was significantly decreased in the coal workers as compared to the control group. Serum potassium and iron concentrations were significantly higher whereas serum sodium was moderately decreased in coal workers as compared to control. MDA levels of all samples were significantly increased in the coal workers as compared to the control group. SOD activity in serum and erythrocyte was significantly lower in the coal miner group as compared to the control group. The present study demostrated that the elevated MDA and iron levels and insufficiency of antioxidant potential in serum and erythrocytes cause a decrease in erythrocyte Na+, K+ -ATPase enzyme activity in coal miners as compared to normal subjects.