SummaryWe estimated the number of cancers attributed to occupational exposures in Spain, and examined the prevalence of carcinogenic exposures in the workplace.We used population, labour, mortality and morbidity statistics and applied an approach used by Doll and Peto for the population of the USA.In men, 6% and in women 1% of all cancers can be attributed to occupational exposures. Lung cancer accounts for 62% of all occupational cancers. About 402,346 men and women are employed in industries or occupations entailing a well recognised carcinogenic risk. In addition, a large but unquantifiable number of workers are employed in various other occupations and industries where exposure to carcinogenic chemical or physical agents may occur.The i...