Due to its remarkable physical properties asbestos has been widely used in the industry. It is estimated that 25% of present French retired workers have been occupationally exposed to asbestos. A causal relationship between asbestos exposure and respiratory cancers is established since 1955 for lung cancer, and since 1960 for pleural mesothelioma. A causal relationship is also demonstrated for peritoneal and pericardic mesotheliomas, and strongly suspected for laryngeal cancers. It is estimated that occupational exposure to asbestos could be responsible for 5 to 20% of lung cancers and 80 to 90% of pleural mesothelioma, in men, in industrialized countries. The risk of cancer is positively correlated to cumulated exposure. No threshold has been demonstrated below which there is no increased risk of respiratory cancer.