The efficacy of radiotherapy in locally advanced non-small-cell lung cancer is limited. One attempt to improve survival uses a combination of radiation and chemotherapy. These two modalities can be applied in sequence or concurrently, but results from phase III trials of combined therapy versus radiation alone have been inconsistent. Early studies were mostly negative, but more recent trials using platinum-based regimens have shown some survival benefit for combined treatments. The positive impact of chemotherapy has also been shown in a meta-analysis. In recent studies, concurrent chemotherapy and radiation appears better than sequential application. However, the benefit of the combined approach is modest and should be balanced against increased early and late toxicity. The role of new agents such as taxanes, vinorelbine, gemcitabine, and topoisomerase inhibitors in combined modality therapy of non-small-cell lung cancer warrants further clinical investigation.