In a study of the possible impact of asbestos exposure on car mechanics, 925 car mechanics and 109 referents (office workers in car-repair firms) were examined. They took part in a health screening in 1977-1981. The forced expiratory volumes in 1 s and the forced vital capacities of the car mechanics were close to the predicted values and did not differ from the findings of the referents. Pleural plaques were found in 41 of the mechanics but in none of the referents. Only minor changes were detected in the chest radiographs ie, 1/1 or less according to the ILO-U/C classification. It is concluded that asbestos exposure can generally cause pleural plaques in car mechanics but no substantial impairment of lung function.