Background: Chest tube drainage (CTD) is an indication for the treatment of pneumothorax, hemothroax and is used after a thoracic surgery. But, in the case of incomplete lung expansion, and/or persistent air leak from CTD, medical or surgical thoracoscopy or, if that is unavailable, limited thoracotomy, should be considered. We evaluate the efficacy of bronchoscopic injection of ethanolamine to control the persistent air leak in patients with CTD. Methods: Patients who had persistent or prolonged air leak from CTD were included, consecutively. We directly injected 1.0 mL solution of 5% ethanolamine oleate into a subsegmental or its distal bronchus, where it is a probable air leakage site, 1 to 21 times using an injection needle through a fiberoptic bronchoscope. Results: A total of 15 patients were enrolled; 14 cases of spontaneous pneumothorax [idiopathic 9, chronic obstructive pulmonary disease (COPD) 3, post-tuberculosis 2] and one case of empyema associated with broncho-pleural fistula. Of these, five were patients with persistent air leak from CTD, just after a surgical therapy, wedge resection with plication for blebs or bullae. With an ethanolamine injection therapy, 12 were successful but three (idiopathic, COPD and post-tuberculosis) failed, and were followed by a surgery (2 cases) or pleurodesis (1 case). Some adverse reactions, such as fever, chest pain and increased radiographic opacities occurred transiently, but resolved without any further events. With success, the time from the procedure to discharge was about 3 days (median). Conclusion: Bronchoscopic ethanolamine injection therapy may be partially useful in controlling air leakage, and reducing the hospital stay in patients with persistent air leak from CTD.