Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality in the United States. Patients with early stage NSCLC have a reasonable chance of cure with surgery, but unfortunately, fewer than half of all newly diagnosed NSCLC patients are surgical candidates. In addition, less than half of all patients treated with surgical resection alone are ultimately cured of their disease. As a result, several studies have emerged over the past decade examining the role of adjuvant chemotherapy as a means of improving outcomes in early-stage NSCLC. This article highlights the background and rationale, as well as the major findings, of each of these studies, namely, the British Medical Journal meta-analysis, the Adjuvant Lung Project Italy study, the Japanese Lung Cancer Research Group study, the International Adjuvant Lung Cancer Trial, the Cancer and Leukemia Group B 9633 study, and the JBR.10 study. From these collective studies, a new standard of care has emerged in the treatment of early-stage resected NSCLC: the use of adjuvant platinum-based chemotherapy.