The relationship between asbestos and mesothelioma has been well delineated in the past. The epidemiologic, clinical, radiologic, and pathologic features of mesothelioma are discussed with reference to the diagnostic evaluation of asbestos-exposed patients. The extensive epidemiologic data correlating asbestos, tobacco smoke, and induction of lung carcinoma are also reviewed. These data provide a model for evaluation of other occupationally induced lung carcinogens such as organic and metallic industrial inhalants.