Non-small cell lung cancer (NSCLC) constitutes approximately 85% of all lung cancers, with patients having a poor prognosis. Approximately one third of NSCLC patients present with early-stage disease in which potentially curative resection and multi-modality therapy. Although adjuvant chemotherapy is the standard practice for patients with stages I-III breast and colorectal cancer, the therapeutic efficacy of adjuvant chemotherapy, following complete surgical resection of early stage NSCLC, has not been fully established. Several prospective randomized trials for patients with early stage NSCLC (stages I-IIIA) have confirmed a survival benefit with cisplatin-based adjuvant chemotherapy, as demonstrated in the 1995 meta-analysis performed by the NSCLC Collaborative Group. Studies from Japan have reported that adjuvant therapy with uracil-tegaful (UFT) afforded an improvement of 4% in the 5-year survival rate and a relative risk reduction of 26% in mortality at 5 years among patients with T1-2N0 (stage I) disease. In particular, the Japan Lung Cancer Research Group has demonstrated an improvement in the 5-year survival rate of 11%, favoring chemotherapy with UFT in the subset of patients with T2N0 (stage IB) disease. Two published meta-analyses based on abstracts have estimated a relative risk reduction in mortality of 11-13% at 5 years. The Lung Adjuvant Cisplatin Evaluation (LACE), which was based on a pooled analysis of five randomized trials, has demonstrated that cisplatin-based adjuvant chemotherapy improved survival in patients with completely resected NSCLC. This benefit depended on stage, being greatest in patients with stage II or IIIA disease. This analysis has suggested that platinum-based adjuvant chemotherapy may have no benefit for patients with stage IA and only a marginal benefit for patients with stage IB. Thus, the information available at the current time supports the administration of adjuvant chemotherapy for patients who have undergone complete resection of stages IB-IIIA NSCLC. Further research is needed to define the role of adjuvant platinum-based chemotherapy and its use, in conjunction with chest radiotherapy as the treatment for patients with resected stages IB and IIIA NSCLC.