A study was carried out on the mortality of 3741 individuals who worked in a factory making railway rolling stock, in which crocidolite was used to insulate the coaches in the 60's and 70's. Employees who had worked in the factory between 1960 and 1995 were included in the study, with the main aim of investigating cancer mortality in these subjects. 9 cases of mesothelioma were known in this factory before starting the study. The follow-up was performed from 1960 to 1996. The SMR's for lung cancer and mesothelioma in 2737 blue-collar workers were 1.23 (CI 95% = 1.00-1.50) and 6.50 (CI 95% = 2.96-12.38) respectively, based on national rates. The excesses were mainly found among subjects who had worked before 1970 with duration of employment exceeding 20 years.