The management of parapneumonic empyema remains controversial. We present the management of 20 children with empyema who were referred to The Royal Brompton Hospital, over a 5-year period from January 1990 to December 1994. Prior to referral, only 12 of the 20 patients had undergone thoracocentesis, all confirming the diagnosis of empyerna. Six of these 12 patients then underwent closed chest tube drainage. There was a 2 to 32 day (median, 8 days) delay from initial hospital presentation to referral. Following referral 13 of the 20 patients were assessed as having persistence of clinical symptoms and radiological appearances making recovery with continued conservative management unlikely. These patients had a thoracotomy with decortication within 2 days. The remaining 7 were initially treated with closed chest tube drainage, but 5 subsequently required decortication. All patients made an uneventful postoperative recovery and were discharged within 3-1 1 days (mean, 6.8 days). Four patients were subsequently found to have a significant underlying immunological defect. We conclude that there is a lack of agreement regarding the initial management of parapneumonic empyema. In our experience, decortication gives excellent results in those children not responding to medical treatment within 7-10 days. In experienced hands this technique is safe with rapid resolution. All patients who present with empyema should be screened for immunological abnormalities.