Lung cancer remains one of the top five cancers worldwide. Around 85% are nonsmall cell lung cancer (NSCLC) and only one-third present with early stage diseases. Radiotherapy had an important role both in radical and palliative treatment. With advancement in technology, newer techniques of stereotactic body radiotherapy allow delivery of much higher biologically effective dose to tumor achieving similar outcomes to radical surgery in early stage diseases. However, the usually large tumor volume together with preexiting poor lung condition makes radiotherapy challenging to deliver a radical dose to tumor while maintaining normal tissue constrains. In this chapter, different indications and techniques used in treating NSCLC will be discussed and reviewed.