Malign mesothelioma is a pleural neoplasia related to the occupational exposure to asbestos, although other factors can be involved; its incidence is increasing in Western Europe. Pain in the thorax and dyspnoea are its most frequent clinical manifestations. An important role in the evaluation of the disease is played by imaging techniques, of which CAT is the most widely used, although MR and PET are suggested as techniques that can provide additional information in the diagnosis and prognosis of these patients. Survival is short and there is no consensus in the literature that would orientate treatment of these patients. This is due to a lack of data that would confirm an increase of survival with any therapeutic method, although recent efforts have led to the development of new treatments that could change the present pessimistic view of the disease held by doctors and patients.