We report a prospective multi-centre study of the clinical course and hospital management of thoracic empyema in 119 patients (mean age 54.8). The commonest presenting symptom was malaise (75%), 55% were febrile; 31% were previously well with no predisposing condition. Initial treatments were antibiotics alone (5), needle aspirations (46), intercostal tube drainage (61), rib resection (3) and decortication (4). Overall, intercostal drainage was used in 77 patients (16 failed aspirations), surgical rib resection in 24 (1 failed aspirations, 20 failed drainage), and surgical decortication in 28 (6 failed aspirations, 17 failed drainage). Only 4 patients received intrapleural fibrinolytic agents. Aspiration and drainage were likely to fail if the empyema was > 40% of the hemithorax. Median time from treatment start to discharge was: aspirations, 26 days; drainage, 23 days; resection 11 days; decortication, 12 days. Overall 21 patients died (12 with empyema as the major cause); two had been surgically treated. Mortality correlated with age, diabetes, heart failure, and low serum albumin at admission. Infecting organisms, identified in 109 patients (92%) included anaerobes (37), Str. melleri (36), and Str. pneumoniae (28). Six months after discharge, all but six survivors had regained their previous health.