Pleural empyema. Retrospective review of 343 patientsBackground: Pleural empyema still has a dismal prognosis. Aim: To describe features and prognostic factors of patients with pleural empyema subjected to surgical procedures. Material and Methods: Retrospective review of 343 patients with pleural empyema (mean age 52 years, 71% males), that were subjected to any type of surgical procedure. Criteria for diagnosis of empyema were a positive culture, a fluid pH of less than 7.2 or a compatible macroscopic appearance of the fluid. Results: Empyema was secondary to pneumonia in 243 patients (71%), secondary to surgical procedures in 41 patients (12%), secondary to trauma in 19 patients (5.5%), secondary to a lung abscess in 10 patients (3%), tuberculous in 10 patients (3%), neoplastic in two cases (0.6%), secondary to pneumothorax in 2 cases (0.6%) and of unknown origin in 13 patients (4%). A microorganism was isolated from pleural fluid in 89 patients (26%). The surgical procedures performed were 251 decortications by thoracotomy (73%), 70 pleurotomies (20%), 11 video assisted surgeries (3%), seven decortications with lung resections and four fenestrations. Complications were recorded in 104 patients (30%), 29 patients were re-operated (8.5%) and 31 died (10%), all due to sepsis. Conclusions: The main cause of pleural empyema is pneumonia. In most patients, microorganisms are not isolated from pleural fluid, thoracotomy with decortication is the most frequent surgical procedure. There is a high rate of complications and mortality.