Surgical resection of early-stage non-small-cell lung cancer (NSCLC) remains the standard of care in patients fit for surgery. Careful preoperative staging is imperative, as is pathologic documentation of the mediastinal nodal contents. Adjuvant postoperative thoracic radiation therapy (RT) clearly has an impact in reducing locoregional recurrence but has no clear impact on survival. The Postoperative RT (PORT) metaanalysis raised concerns about PORT, particularly in stage I/II NSCLC, suggesting it may negatively impact survival. This was not a concern in stage III NSCLC, in which the risk of locoregional recurrence is higher. However, distant recurrence remains the dominant pattern in resected NSCLC, suggesting that the majority of patients with early-stage resected NSCLC harbor occult micrometastatic disease. Historically, the role of adjuvant chemotherapy has been controversial, and its routine use was not supported by the published data, which consisted of a small number of underpowered trials using inadequately delivered, antiquated chemotherapy. More recently, larger trials have been reported with conflicting results. Like adjuvant PORT, chemotherapy combined with RT has not improved survival over PORT alone. The use of adjuvant cisplatin-based therapy did not show a survival advantage in the Adjuvant Lung Project Italy study but did in the International Adjuvant Lung Trial, creating controversy in the routine implementation of adjuvant therapy in all patients. Recently completed randomized trials by the Cancer and Leukemia Group B and the National Cancer Institute of Canada provide convincing evidence of a substantial benefit from adjuvant therapy in well-staged and completely resected stage I/II NSCLC. Currently, the totality of the data supports a discussion with patients with resected NSCLC regarding the potential benefits of adjuvant therapy.