A clinical study was conducted of 17 patients aged less than 40 years who received resection for lung cancer in our department. The 17 cases made up 1.8% of the total series of 924 resected lung cancer cases, with the number of cases increasing as the age of 40 years was approached. The male-female ratio was 1.1:1, with proportion of women higher than in the total series of lung cancer cases. The histological type of included a high proportion of adenocarcinomas (47.0%), while squamous cell carcinomas were few. In addition, the proportion of tumors of low-grade malignancy such as carcinoid tumors and mucoepidermoid carcinomas was high. The majority (58.8%) of cases were detected by mass screening. As a result, the number of stage I cases was high (10 cases, 58.8%), and curative resection could be performed in 70.8%. The prognosis of these young patients did not differ significantly from that of the total resected group, with a 5-year survival rate of 62.4% achieved. It was considered that the prognosis of lung cancer in young persons can also be improved with early detection by mass screening and active surgical intervention.