The purpose of this study was to describe the characteristics and management of pain among patients with nasopharyngeal carcinoma (NPC) prior to and during the 7-week course of radiation therapy (RT) in Taiwan. Twenty-nine men and 11 women with NPC participated in this prospective, longitudinal study. A modified Brief Pain Inventory was used to assess pain and its interference with daily activities weekly. Medical records were reviewed to abstract pain management and disease data. Findings showed that the pain intensity and pain interference scores escalated prominently at Week 3 and peaked at Week 5, representing the time course of RT complications. Pain prior to RT exacerbated the RT-induced mucositis pain. The pain related to RT for NPC was often severe and undertreated, and affected swallowing and talking more than sleeping or other general activities. We recommend interventions to control pain be instituted prior to Week 3 to minimize the potentiation of subsequent pain.