Twenty-two patients, 40 years old or younger, were surgically treated for lung cancer between 1974 and 1989. The male to female ratio was 1.2:1. Ten patients were symptomatic, with the average duration of symptoms being 3.6 months. There were 13 patients with adenocarcinoma and 9 patients with large cell carcinoma. In terms, of postoperative stages, 5 patients were classified in stage I, 10 in stage IIIa, 5 in stage IIIb, and 2 in stage IV. Complete resection was performed in 14 patients, incomplete resection in 6, and exploratory thoracotomy in 2. The 3-year survival rate after complete resection was 66.2% in young patients, which was not significantly different from the 65.2% 3-year survival rate in older patients. There was no significant difference between the young and older groups according to histological cell type and TNM staging. In cases of incomplete resection or exploratory thoracotomy, 4 of 8 patients had been alive more than 2 years after operation. These results suggest that a long-term survival in the young patients is expected to be almost the same as that in the older patients after either complete resection or incomplete resection.