Forty seven cases of malignant pleural mesothelioma were observed at the Monfalcone Hospital between October of 1979 and March of 1988. The large majority of the male patients had been exposed to asbestos (1332214) in the shipbuilding industry, Navy, Merchant Navy, and insulation. The other three men had been employed in the Monfalcone sodium-carbonate (497198) factory, where asbestos exposure had certainly occurred in the past. The latency periods ranged from 20 to 63 years. At necropsy the large majority of the patients demonstrated hyaline pleural plaques. Lung asbestos bodies ranged between 10 and about 10,000,000 per gram of dried tissue, with 21 subjects having more than 10,000 asbestos bodies per gram. The histological examination of lung tissues obtained at necropsy revealed a variable degree of pulmonary asbestosis in 31 of 36 cases. Multiple tumors were observed in seven necropsy cases. Three additional malignancies, beside the mesothelioma, were observed in one 77 year old man: stomach adenocarcinoma, chronic lymphocytic leukemia, and prostate microcarcinoma. Among the women, NOS infiltrating breast carcinoma was associated with the mesothelioma in one case.