BACKGROUND: Known as a kind of complication or a specific form of pulmonary tuberculosis, endobronchial tuberculosis caused several kinds of problems in diagnosis and managements. But the frequency of this disease are is widely variable, generally reported from as low as 10 - 20% to as high as 40 - 50%. We prospectively performed bronchoscopy in patients diagnosed as pulmonary tuberculosis to evaluate the frequency of endobronchial tuberculosis and its related findings. METHOD: From March, 1995 to February, 1996, we prospectively performed bronchoscopy in patients newly diagnosed as pulmonary tuberculosis and evaluated the frequency of endobronchial tuberculosis, its clinical features and laboratory findings including raiologic, microbiologic and physiologic aspects. RESULTS: Number of patients diagnosed as pulmonary tuberculosis was 103 and 55 patients(53.4%) were found to have endobronchial tuberculosis. But the frequency were 43.8% in male and 76.7% in female, respectively. Frequently noted symtoms were nonspecific including cough, sputum, fever, weight loss in the order of frequency but cough was more frequent than in pulmonary tuberculosis. Physical examination showed rale,decreased breathing sound and wheezing and wheezing was more frequent than in pulmonary tuberculosis. All 7 subtypes were noted bronchoscopically and edema-hyperemia (stenotic without fibrosis) type was most frequently(32.7%) noted, and followed by chronic nonspecific bronchitis type stenotic with fibrosis type and actively caseating type in the order of frequency. The relationship between subtypes of endobronchial tuberculosis and radiologic findings was insignificant. Right lung was involved more frequently than left lung and left upper lobe was most commonly involved site, and followed by right upper lobe and trachea. Acid-fast bacilli(AFB) positivity in sputum and / or bronchial washing fluid was 73% and suggested high risk of infectivity. CONCLUSION: The frequency of endobronchial tuberculosis in patients with pulmonary tuberculosis was higher than known and also suggested bronchoscopic examination to detect endobronchial involvement should be recommanded and careful management is also needed to prevent complications.