PURPOSE: This study was carried out to investigate survival rate and the factors affecting survival among lung cancer patients who have been registered in Daejeon Cancer Registry from 1998 to 2000. METHODS: Kaplan-Meier method and Cox proportional hazard model were used to evaluate the factors affecting survival of lung cancer patients. RESULTS: Lung cancer was more common in men than women, with an overall sex ratio in Daejeon, Korea of roughly 3:1. The incidence of lung cancer was 17.1 per 100,000 population in 1998, 21.4 in 1999, and 22.4 in 2000. Average age of incidence was 64.8 years old and 11.7% of study subjects having family history of lung cancer. Forty eight % of lung cancer was diagnosed as Stage III and 40.6% as Stage IV. Histologically, squamous cell carcinoma was 39.7% of all and most frequent, and then adenocarcinoma 25.5%, and small cell carcinoma 19.3%. 3-year survival rate of female was higher than that of males, and that of smoker was the lowest among groups according to the smoking level. Survival rate by age fell dramatically in group over 70 years. Lung cancer patients diagnosed as Stage III and Stage IV had a much lower survival rate than those diagnosed as Stage I or II. Stage, LDH and age were proved to be important variables that affect the mortality of lung cancer patients. CONCLUSION: We found that the stage at diagnosis was a critical factor that affected the survival of lung cancer patients from this study. So It is essential to develop early diagnosis of lung cancer and then it needs to evaluate the effectiveness of that.