In this study, we evaluated the results of surgical treatment in young adults and compared the clinico-pathological features between young and elderly patients. We reviewed the clinical records of 1185 lung cancer patients who underwent surgery in our department. A total of 20 (1.7%) primary lung cancer patients (14 men and 6 women) < or =40 years of age were retrieved. The age range was from 26 to 40 years. Histological type included 10 adenocarcinomas (50%), 3 large cell carcinomas (15%), 3 carcinoids (15%), 2 squamous cell carcinomas (10%), and 2 others. The surgical procedure included 7 (35%) pneumonectomies, 11 (55.0%) lobectomies, and 1 (5%) partial resection. The proportion of pneumonectomies was significantly higher than among elderly patients. Clinical stage was underestimated in 7 of 20 patients, and among these, mediastinal lymph node metastases were revealed by pathological examination in 6 patients. Postoperative 5-year survival rates were 50.2%, 50.4%, and 43.8% in patients < or =40, 41-70, and > or =71 years old, respectively. There were no significant differences in survival rates between younger group and elderly groups. This study suggests that surgical resection is also recommended as the first-line treatment for younger patients with lung cancer.