Survival rates were studied in 1,297 screen-detected and 1297 symptom-detected patients with lung cancer. Resections took place in 20 hospitals and institutions in the Japanese Lung Cancer Screening Research Group. 60.6% of the screen-detected lung cancer patients were from stage 0 to 11 and 39.4% were from stage III and TV. On the other hand, 27.1% of symptom-detected patients were from stage 0 to 11 and 72.9% were stage III to IV. In the screen-detected group, the tumor was peripheral in 83%, adenocarcinoma in 52.4% and the resectability rate was 66.5%. Five- and 10-year survival rates were 32.4% and 22.5% respectively in the screen-detected patients and 13.7% and 9.9% in symptom-detected patients.