To summarize the experience in the diagnosis of pleural mesothelioma. Analysing the clinical data of 19 patients with pleural mesothelioma, including age, history of exposure to asbestos, clinical manifestations, imaging and laboratory examinations and metastases. None of the 19 patients had history of exposure to asbestos. Eight cases(42.1%) had no obvious thoracodynia, 9 cases(47.4%) had pleural effusion limited to the right chest, and in 2 cases(10.5%) the brachialis plexus was involved, and in 1 case (5.3%) malignant mesothelial cells were detected in the pleural effusion. Pleural thickening or nodules were found in 13 cases on CT and in 9 cases by B ultrasonographic examination. Exposure to asbestos is not the only cause of pleural mesothelioma. Chest pain is not always associated with pleural mesothelioma. CT and B ultrasonography are of good help in the diagnosis of pleural mesothelioma.