BACKGROUND: The presence of emphysema on computed tomography (CT) is associated with an increased frequency of lung cancer, but the postoperative outcomes of patients with pulmonary emphysema are not well known. The objective of this study was to investigate the association between the extent of emphysema and long-term outcomes, as well as mortality and postoperative complications, in early-stage lung cancer patients after pulmonary resection. METHODS: The clinical records of 566 consecutive lung cancer patients who underwent pulmonary resection in our department were retrospectively reviewed. Among these, the data sets of 364 pathological stage I patients were available. The associations between the extent of lung emphysema and long-term outcomes and postoperative complications were investigated. Emphysema was assessed on the basis of semiquantitative CT. Surgery-related complications of Grade ≥ II according to the Clavien-Dindo classification were included in this study. RESULTS: Emphysema was present in 63 patients. The overall survival and relapse-free survival of the non-emphysema and emphysema groups at 5 years were 89.0 and 61.3% (P < 0.001), respectively, and 81.0 and 51.7%, respectively (P < 0.001). On multivariate analysis, significant prognostic factors were emphysema, higher smoking index, and higher histologic grade (p < 0.05). Significant risk factors for poor recurrence-free survival were emphysema, higher smoking index, higher histologic grade, and presence of pleural invasion (P < 0.05). Regarding Grade ≥ II postoperative complications, pneumonia and supraventricular tachycardia were more frequent in the emphysema group than in the non-emphysema group (P = 0.003 and P = 0.021, respectively). CONCLUSION: The presence of emphysema affects the long-term outcomes and the development of postoperative complications in early-stage lung cancer patients.