BACKGROUND: Even though lung cancer has become a major cancer in Korea, national survey for lung cancer is not available except several reports from individual hospitals. METHODS: The Korean academy of tuberculosis and respiratory disease investigated and analysed retrospectively the characteristics of primary lung cancer diagnosed in 1997 from general hospitals in Korea. RESULTS: Among 3,795 patients, 76.6% of the patients are smokers and 79.3% are male. Squamous cell carcinoma is the leading type of lung cancer(44.7%) followed by adenocarcinoma(27.9%). Smoking rate in adenocarcinoma was significantly lower than in squamous cell carcinoma and small cell cancer. Cough is the most common symptom, however, 7.2% are asymptomatic. Bronchoscopic biopsy has a main role in the diagnosis of squamous cell carcinoma and small cell cancer but percutaneous needle biopsy has more important role in adenocarcinoma. Two-thirds of NSCLC patient were found in unresectable advanced stages. CONCLUSION: In contrast to other countries, squamous cell carcinoma is still the most frequent type of lung cancer. High proportion of smoker and advanced, unresectable lung cancer necessitates the development of program for cessation of smoking and early detection.