We aimed to review the development of the chemoradiotherapy options used in the treatment of locally advanced, unresectable or medically inoperable Stage III non-small-cell lung cancer (NSCLC) patients with this review. There are many differences about extent and localization of disease for locally advanced stage NSCLC. The optimal management depends upon multiple factors, including the specific combination of tumor (T) and node (N) staging parameters, the potential to achieve a complete surgical resection of all disease if indicated, and the patient's overall condition and preferences. Chemoradiotherapy has always been the cornerstone of treatment of locally advanced NSCLC and techniques have significantly advanced over this time. Radiation oncology needs to develop the new techniques to improve their survival and the toxicity associated with treatment.