Objective: Progression of empyema, with the development of fibrinous adhesions and loculations, makes simple drainage difficult or impossible. The appropriate management remains controversial. Intrapleural fibrinolytic treatment to facilitate drainage of loculated empyema instead of open thoracototny has been advocated recently. The aim of this study was to evaluate the effectiveness of the intrapleural fibrinolytic application. Methods: In our clinic we used urokinase in 28 patients and performed thoracotomy and decortication in another 43. The two groups of patients had similar characteristics. Mean age was 10.2 (range: 3-14 years). All had undergone medical treatment and tube thoracostomy. Empyema severity score (ESS) was measured in all. Results: Fibrinolytic treatment, and thoracototny and decortication had complete response rates of 67.8 and 100%, respectively. Treatment was ineffective in six (21.4%) out of 28 patients who underwent urokinase instillation; they recovered after thoracotomy. In three (10.7%) patients, partial resolution was observed. One patient died of sepsis and pleural hemorrhage. Mean hospital stay after urokinase was 10.7 (range: 6-17) days. In the thoracotomy group, all patients recovered completely. No deaths occurred. Postoperative complications were incisional infection in two patients, atelectasis in one and reoperation after hemorrhage in one. Mean hospital stay after surgery was 9.5 (5-19) days. The ESS of cases operated on was lower postoperatively (0.3 versus 0.8). Conclusion: Continued conservative therapy risks morbidity and mortality. Thoracotomy-decortication can be used successfully and must remain the preferred method in the treatment of multiloculated pediatric empyema. (C) 2002 Elsevier Science B.V. All rights reserved.