To identify the benefits of limited surgery on small-sized lung tumors, the following subjects are discussed: 1) an updated report from a prospective group study (January 1992-December 1994) for extended segmentectomy for small lung tumors (n = 55); 2) a histopathological study of resected adenocarcinoma specimens less than 2 cm in size (n = 94), proposed by Noguchi; and 3) lung function after limited surgery and the quality of video-assisted thoracoscopic surgery.1) Among 10 deaths, 4 patients died of their disease including one with local recurrence. The survival rate at 5 years was 91%, not including 6 unrelated deaths. 2) Of 94 patients, twelve with localized bronchioalveolar tumors (type A and B), and 23 of 57 patients with active fibroblastic proliferation (type C), underwent extended segmentectomy. Those 35 patients are all free of disease. The remaining 59 patients had a 70% 5-year survival rate. 3) Forced vital capacity was maintained at 92% of the preoperative level, which was much better than 81% for patients undergoing lobectomy. Card-sized thoracotomy using a thoracoscope was carried out in 92 patients, including 21 patients who underwent segmentectomy, in a series of 175 consecutive lung cancer operations. This approach resulted in less bleeding, the same operating time, and better preservation of vital capacity.Extended segmentectomy for small lung tumors did not affect the prognosis, and was associated with a better quality of life postoperatively.