Pain from radiation therapy (RT)-induced mucositis is a significant clinical problem for patients with head and neck cancer (HNC). The purpose of this study was to determine the pattern, severity, and time course of RT-induced mucositis pain; self-care behaviors (SCBs) used to manage mucositis pain; and the effectiveness of these behaviors in relieving such pain. Forty-nine patients with HNC were assessed using the MacDibbs Mouth Assessment Tool to determine the severity of RT-induced mucositis pain over their course of RT and at a one-month follow-up visit. All patients developed pain due to RT-induced mucositis. A Self-Care Diary was used weekly by patients to record SCBs and their effectiveness. The most effective SCBs for RT-induced mucositis pain were mouth rinsing and using oral analgesics. However, more severe pain with swallowing was not managed well throughout the study. Future studies need to test more effective strategies to manage RT-induced mucositis pain.