The results of the clinical observations on the bronchogenic carcinoma of forty-five cases treated in the Department of Thoracic and Cardiovascular Surgery, Chungnam National University Hospital, during the period of 6 years from June.1978 to Aug. 1984, are as follows: 1. Of 45 cases, 44 cases were over 40 years of age and the sex ratio was 4.6:1 in male`s favor. 3. Among 50 cases, 45 cases were confirmed histopathologically. Of these, 30 cases [66.7%] were squamous cell carcinoma, 8 cases [17.8%] adenocarcinoma, and 7 cases [15.6%] undifferentiated cell carcinoma. 4. The thoracotomy was performed in 31 cases [68.9%] of 45 cases and the resection of the lesion in 16 cases [51.6%]. The empyema and bronchopleural fistula developed in 2 cases.