PURPOSE: The author tried to compare the therapeutic effectiveness of urokinase instillation via PCD catheter with other conventional therapeutic modalities such as thoracentesis, closed thoracostomy and percutaneou scatheter drainage in the management of patients with early and late stage II empyema. MATERIALS AND METHODS: Twenty seven of early and 19 of late stage II empyema patients were reviewed. We compared each results of the treatments including the average hospitalization day, success rate, and interval between first procedure and 75% improvement on simple chest film. RESULTS: The average hospitalization day and improvement interval of stage II empyema patients, who were treated with urokinase instillation via PCD catheter, were shortest of all. In earlystage II, they were 11.8 and 8.5 days, and 16.7 and 9.4 days in late stage II patients. In each patient with early and late stage II empyema, they were 17.2, 11.5 days and 24.3, 16.2 days with thoracentesis, 48.0, 32.3 days and 37.7, 24.0 days with closed thoracostomy, 35.2, 17.2 days and 34.8, 20.0 days with percutaneous cathter drainage. All patients treated with intracavitary urokinase showed complete drainage of empyema. CONCLUSION: Intracavitary urokinase facilitates percutaneous catheter drainage of empyema, with resultant reduction of hospitalization days. Also this method has high success rate.