Although surgery offers the best chance of cure for patients with early stage (I-resectable III A) non-small cell lung cancer (NSCLC), the overall 5-year survival rate is modest, and systematic improvements are needed. In the 1990s, two small prospective randomized phase III trials demonstrated striking results with neo-adjuvant chemotherapy and therefore several randomized trials were performed. However, there was no statistical significant trial among them. The recent systematic meta-analysis based on 8 trials revealed hazard ratio was 0.88 (95%CI: 0.76-1.01), although these data suggested a 12% relative benefit with the neoadjuvant chemotherapy, equivalent to an absolute improvement in survival of 5% at 5 years. For patients with stage N2-III A NSCLC, US intergroup trial (INT0139) also demonstrated there was no statistical difference between chemoradiotherapy following surgery and chemoradiotherapy on overall survival. At present, there is no scientific evidence of the neoadjuvant strategy for early stage NSCLC in practice. This invasive treatment is still investigational and should be done as the clinical trial base.