We have summarized the current role of surgery for primary lung cancer based on solid evidence from clinical trials. Notably, LCSG 821 is the sole clinical trial that has compared lobectomy with limited resection for early stage non-small cell lung cancer (NSCLC). This study demonstrated that limited resection led to a three-fold increase in locoregional recurrence and a 30% increase in mortality. Lobectomy has been the standard procedure based on the results of this single study, which was conducted in 1980's. Four clinical trials compared mediastinal lymph node dissection with sampling; however, all except 1 failed to demonstrate the survival benefit to lymph node dissection. The role of mediastinal lymph node dissection should be a more precise staging of mediastinal lymph node metastases. The role of surgery for NSCLC with mediastinal lymph node metastasis (ie, stage III A/N2)has not been proven in clinical trials. Because of the heterogeneity of patients with stage III A/N2 NSCLC, current guidelines recommend a multi-disciplinary discussion for each case. Superior sulcus tumor, which invades the chest wall, including the first rib, is a challenging operation for surgeons. Two phase II studies(in the United States and Japan) demonstrated that induction chemoradiotherapy followed by surgery offered promising results, with an approximately 70% complete resection rate and a 50%survival rate at 5 years. Video-assisted thoracic surgery(VATS)was evaluated in a multiinstitutional phase II study, which concluded that this approach is feasible for early stage NSCLC. However, significant evidence was accumulated based on retrospective cohort studies, and VATS lobectomy has become popular in daily practice.