One hundred and thirteen patients underwent diagnostic fiberoptic bronchoscopy to exclude the presence of the lung cancer at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital from January 1979, to July 1980. Sixty five cases of these patients were studied for passible lung cancer by bronchoscopic examination. Patients varied in age from 24 to 75 years, with the highest concentration lying in the sixth decade (49%). male was predominated with sex ratio of 6.3 : 1. Forth three (75.4%) of 57 cases impressed as definitive, and 8(14.5%) of 55 cases impressed as negatibe lung cancer were subsequently proved to have had lung cancer. Positive bronchoscopic biopsy was found in 10 of 14 lung cancers which were situated in the left main bronchus and in 11 of 13 neoplasms involving the right upper lobe bronchus. epidermoid cell carcinomas were most frequent(82.4%). Bronchial biopsy detected 34(79%) of 43 hilar cancers and 1.3(59%) 22 periphera neoplasms, in those patients who had fiberoptic bronchoscopic examinations. In the present series of 65 cases, the lesion was so far advanced when first seen that it was considered inoperable in 31 (47.7%) and operable 34(52.3%), 19(55.9%) of these refusing surgery. fifteen were explored of whom 12(80%) were resectable.