All cases of pleural malignant mesothelioma occurring in Tuscany were collected, backdated to 1980 (to 1970 for the provinces of Florence and Prato; to 1975 for the provinces of Pisa and Siena), in order to evaluate the incidence of occupational exposure to asbestos. The aim was to enhance primary prevention in those workplaces still at risk nowadays. To achieve information on the possible occupational, domestic or environmental exposure, an interview was conducted using a semi-structured questionnaire. An exposure classification was produced to focus preventive intervention. This surveillance system needs to be developed to contribute to epidemiological research, especially on the effects of low level exposures, and to primary prevention.