BACKGROUND: Lung abscess is an accumulation of pus within a destroyed portion of the lung. Antibiotic therapy and postural drainge has proven to be an effective method of treatment for the majority of patients with pyogenic lung abscess. When medical therapy fails, thoracotomy and pulmonary resection are the current therapies. Empyema is pus in the pleural space, and this term is reserved for effusions on which the Gram stain of the pleural fluid is positive. Initially, such collection may be drained via chest tube. Recently, in patients who are judged to be unsuitable for surgery and are in poor condition, percutaneous drainage using pig-tail catheter has been performed. We report our experience with 10 cases of lung abscess and 23 cases of empyema who were treated by percutaneous pig-tail catheter drainage. SUBJECTS AND METHODS: Our study included 10 patients with lung abscess and 23 patients with empyema who were treated by percutaneous pig-tail catheter drainage, from January, 1990, to May, 1996, at Hanyang University then a pig-tail catheter was inserted into the abscess or the site of empyema under fluoroscopic and ultrasonograpic guidance. Following aspiration, the catheter was sutured into the skin, and connected to the suction tip. Catheter drainage was discontinued when the abscess or empyema was resolved in radiologically and clinically. RESULTS: There were 2 cases of lung abscess caused by Staphylococcus aureus and Klebsiella pneumoniae and 14 cases of empyema caused by M. tuberculosis. The others were unknown. The duration of drainage was 1-2 weeks in 7 cases of lung abscess and 14 cases of empyema. In the 29 of 33 patients, percutaneous drainage were carried out successfully. 20 of the 29 cases rapidly improved. CONCLUSION: Percutaneous drainge is effective and relatively safe for management of lung abscess or empyema refractory to medical therapy or poor candidates for surgical treatment.