It is needless to say that early diagnosis and appropriate treatment for endobronchial tuberculosis are most important, and bronchoscopic examination is necessary for early diagnosis. Although endobronchial tuberculosis frequently causes bronchial stenosis, there are no specific therapies to prevent the complication. To determine the effectiveness of corticosteroids in the prevention of complication of endobronchial tuberculosis, this study was undertaken. 18 patients with endobronchial tuberculosis whose bronchoscopic findings showing ulcer formation or endobronchial polyp, out of 35 patients with endobronchial tuberculosis who were treated in Nihon University hospital from 1996 to 1998, were evaluated to determine the effectiveness of corticosteroids in the prevention of bronchial stenosis. We divided the patients into 2 groups: 11 who received systemic chemotherapy for tuberculosis only, and 7 who received systemic chemotherapy combined with oral corticosteroid. No significant differences distinguished the groups with respect to duration of positive sputum culture or reduction of respiratory symptoms. However, a significant alleviation of bronchial stenosis was observed in the patients who received systemic chemotherapy combined with oral corticosteroid. This study suggested that corticosteroid therapy in addition to standard chemotherapy for tuberculosis was effective for prevention of complication of endobronchial tuberculosis, such as bronchostenosis.