Background: The prognosis for young patients generally considered to be poor. The purpose of this study was to determined whether the clinical characteristics and the survival rate in young lung cancer patients after surgical treatment differs from that in older patients. Material and Method: Of 526 patients, 28(5.3%) were 30 to 40 years old. We studied the clinical characteristics and prognosis of 28 patients aged 40 years or less(Group 1), in whom primary lung cancer was diagnosed and operated between 1990 and 1997, and compared them with those 498 patients aged more than 40 years(Group 2). Result: The differences in sex ratio that were higher for women in Group 1, but there was no significant difference (p=0.297). The percentages for smokers and symptoms in Group 1 were significantly less than in Group 2.(p=0.049, p=0.008). Adenocarcinoma was significantly more common (p=0.018) and squamous cell diagnosed was diagnosed as stage IIIb or stage IV in 9 patients(32.1%), while 12.0% of the patients older than 40 years of age had either stage IIIb or stage IV(p=0.002). The 5-year survival rate was 41.3% in Group 1 ; 37.7% in Group 2, and the median survival time was 24.3 months in Group 1 ; 27.0 months is Group 2. There were no significant difference in survival between two age groups(p=0.808). Conclusion: Younger patients have more adenocarcinoma, however have less squamous cell carcinoma, less symptoms and less smoking history. Although younger patients tended to have more advanced disease and less complete resection rate, the recurrence and the long term survival in these patients did not differ that of older patients.