Radiotherapy has an expanding role in all phases of treatment of nonsmall cell lung cancer. Evolutions in technique, such as three-dimensional conformal radiotherapy, hold the promise for more effective treatment of patients with early stage disease who are not candidates for surgical intervention. Multimodality therapy for patients with locally advanced disease is evolving rapidly, with evidence accruing as to the optimal schedules and doses of radiotherapy and combination chemotherapy. Palliative dose schedules are being refined that maximize patient comfort while providing substantial symptom relief.