Examination for lung asbestos bodies and pleural plaques was made in 996 consecutive unselected autopsies in Torino. The prevalence of asbestos bodies was 12.4% and that of pleural plaques 19.1%. Both findings were found with significantly greater frequency in men, and in the age group above 50 years. In addition, their occurrence increased with age up to 70 years, then decreased thereafter. A significant association between the severity of plaque lesions and the presence of asbestos bodies was found, whereas the number of asbestos bodies was not related to the presence of pleural plaques. It is suggested that pleural plaques are more reliable markers of asbestos exposure started many years earlier, and that lung asbestos bodies are more reliable indicators of more recent exposure.