For the diagnosis of bronchogenic cancer, there are many diagnostic methods including radiologic evaluation,bronchography, sputum cytology and biopsy. In 65 cases of histologically proven bronchogenic cancer in SeoulNational University Hospital during the period from August 1966 to July 1971, the bronchographic finding ofbronchogenic cancer was analyzed, and its diagnostic accuracy was compared with other procedures. The results wereas follows; 1. The bronchography was carried out in 51 cases in which bronchial block was most frequent sign (29 cases; "Amputation" 15 cases and "Cut-off" 14 cases). The next frequent signs were "Stretching" and "Asymmetricalnarrowing" in same frequencies (each 7 cases). negative finding was 5 cases. 2. The over all diagnostic accuracyof bronchography was 90%, and according to the location revealed hilar 100%, middle 93% and peripheral 63%. 3. Thebronchoscopy showed 74% accuracy when combined procedures of gross inspection, washing and biopsy have carriedout. As the location, 94% accuracy in hilar and 65% in middle. Sputum cytology had 24% accuracy. 4. The mostfrequent fidning of plain chest film was circumscribed mass as in 24 cases. But the bronchial block was mostfrequently seen in atelectasis.