A series of 140 patients with malignant pleural mesothelioma is reported. Clinical presentation was delayed in cases without a large effusion, but there was extensive tumour at presentation, shown by thoracoscopy, thoracotomy or computed tomography, in all patients investigated. Thoracoscopy was a useful diagnostic alternative to thoracotomy. With progression of disease, mesothelial extension was more important than distant metastases, which were usually too small and sparse to produce symptoms. Skin deposits of tumour in sites of previous invasive procedures did not cause pain or other clinical problems, and we consider that diagnostic and therapeutic procedures should not be withheld to avoid them. In the management of recurrent pleural effusions, intrapleural bleomycin, preceded by aspiration and followed by suction, was a useful alternative to surgery. Pneumothorax, spontaneous or iatrogenic, required decortication. Adequate pain relief was difficult; radiotherapy and nerve blocking procedures were not effective and opiates were often necessary.