AbstractEighteen patients with malignant mesothelioma were seen at Kure Mutual Aid Hospital over a 10-year period. According to occupational history, chest x-ray manifestations, and evidence of asbestos bodies in the tissue, 13 of these cases were definitely thought to be due to exposure to asbestos as a result of two or three of these items testing positive. Kure City is one of the major ship-building cities in Japan since the 1920s. Most of the 18 patients worked in ship building before and during World War II. Malignant mesothelioma appeared about 40 years after their first exposure to asbestos. In western countries, most malignant mesotheliomas are thought to be induced by exposure to asbestos fibers (1,2). Consequently, there has been a serious effort to deal with this problem recently, including lowering rate of exposure. In Japan, however, there have been few reports that asbestos fibers caused malignant mesothelioma (3). This report suggests that an increased incidence of malignant mesotheliomas in a specific area of Japan may also be due to exposure to asbestos fibers.