Locally advanced lung cancer carries a poor prognosis, and its treatment continues to challenge medical, radiation, and surgical oncologists. While systemic chemotherapy has improved the survival of patients with small cell lung cancer (SCLC), the role and timing of thoracic radiotherapy has not been clearly defined. The roles of chemotherapy and radiotherapy appear to be reversed in the treatment of locally advanced non-small cell lung cancer (NSCLC). The routine use of thoracic radiotherapy has been shown to improve local control after surgery without affecting survival, due to a high incidence of distant metastases. This contrasts with the marginal survival benefit seen with chemotherapy in NSCLC. Nevertheless, the results of recent clinical trials in both SCLC and NSCLC are encouraging and support continued investigation. These studies and the results of recent pilot studies suggest that a closer integration of chemotherapy and radiotherapy (concomitant chemoradiotherapy) may be necessary for further improvement in outcome. This review will present the results of recent studies in systemic therapy of lung cancer and the evidence supporting concomitant chemoradiotherapeutic treatment of this disease.