Between 1984 and 2000 in the Thoracic Surgery Centre pneumonectomies were performed in 947 patients. Postpneumonectomy empyema (PE) occurred in 67 (7%) patients. The aim of this paper were: analysis the reasons of postpneumonectomy empyema appearance, defined bacterial flora, clinical course and optimal management. The causes of PE were: pleural cavity haematoma (20 patients-29.8%), wound suppuration (18 patients-26.8%), bronchial fistula (31 patients-46.2%). These complications appeared singly or together in 49 (73.1%) patients. In 2 (3.0%) patients a long treatment in the Intensive Care Unit because of postoperative shock was the cause of infection. In 3 (4.5%) cases the cause of empyema was associated with infection during the operation. In 13(19.4%) cases the cause of empyema was not established. In 55 patients infections of pleural cavities were diagnosed in the first 8 weeks after operations. In 12 patients empyemas were established later. 12 (17.9%) patients died during the analyzed 1 year period after operation. In 18 (26.9%) patients infections were caused by only one bacterial strain and in 49 (73.1%) by two or three bacterial strains. The different methods of treatment (thoracentesis, drainage, operation) depending on general condition of patient were done.