The incidence of malignant mesothelioma continues to increase in the countries where the use of asbestos remains unregulated. Although a clear history of asbestos exposure is not always obtained, a history of heavy exposure makes the diagnosis more likely in a patient with a malignant pleural process. Cigarette smoking, however, does not place a patient at increased risk for the development of mesothelioma. Symptoms, signs, and laboratory test results are generally not specific for the disease. Most patients present with aching nonpleuritic chest pain and or dyspnea.