Lung cancer is the leading cause of cancer mortality in the United States for both men and women. Twenty to thirty percent of patients with non-small cell lung cancer (NSCLC) present with locally advanced, unresectable tumors. While small improvements in outcome have occurred for this group of patients in the last decade, 5-year survival remains low, ranging from 5 to 20%. Distant metastases and loco-regional progression remain significant patterns of failure. Up to the late 1980s, the standard management was conventional thoracic radiotherapy for locally advanced NSCLC, but when treated with radiotherapy alone, less than 10% of patients survived for 5 years or more. Sixty to seventy percent failed at distant sites and less than 20% achieved durable local control. The addition of chemotherapy reduces the rate of distant failure, improves survival and the combination of chemotherapy and radiotherapy has become the standard of care of patients with locally advanced NSCLC. Current developments aim to optimise individual components of combined modality schedules, increase their synergism and minimise toxicity.