Although surgical resection remains the best potentially curative treatment for non-small cell lung cancer (NSCLC), more than half the patients undergoing resection will eventually die of recurrent disease. Approximately two thirds of relapses occur outside the chest, indicating a potential role for adjuvant chemotherapy. Indeed, a meta-analysis has suggested an absolute survival benefit of 5% at 5 years with adjuvant cisplatin-based regimens. This finding has incited several large-scale randomized trials, the largest of which, the International Adjuvant Lung Trial, has confirmed a similar survival advantage. Conversely, a meta-analysis on postoperative radiotherapy has suggested a detrimental effect, especially for stage I and II patients, that is related most probably to a poor radiation technique. Its value for stage III remains controversial: the observed reduction in local failure did not translate into a survival benefit. In this article, the current status of adjuvant chemotherapy and radiotherapy are reviewed, and future prospects are discussed.