Thoracoscopic operations were performed on 91 patients. In 52 patients operated on by thoracoscopic pleurodesis for pneumothorax, the results were compared with the results in 41 patients previously operated on by transaxillary thoracotomy. The groups did not differ with respect to duration of stay in hospital or minor complications, but the duration of postoperative sick leave was significantly reduced after thoracoscopic operation. In nine cases lung metastasis or primary lung tumours were removed thoracoscopically. Thoracoscopic evacuation were performed in seven cases of empyema or pleural haematoma. Two of these patients were later operated on by open decortication. The main advantages of thoracoscopic surgery are less postoperative pain and a shorter time away from work after operation than with open procedures.