Radiation therapy is a key component of the multidisciplinary treatment of nasopharyngeal and oropharyngeal carcinomas, which are ideal tumors for intensity-modulated radiation therapy (IMRT) because of their location and intimate relationship to the surrounding critical structures. Several studies have suggested that IMRT is superior to conventional radiation therapy in salivary preservation and holds promise for improved locoregional control of these tumors. Target delineation for IMRT in these tumors is complex and requires detailed knowledge of head and neck anatomy and pathways of tumor spread. This article focuses on target delineation for IMRT for oropharyngeal and nasopharyngeal carcinomas. In addition, we also present data on the use of stereotactic radiotherapy as a boost to improve local control of nasopharyngeal carcinomas.