Nasopharyngeal carcinoma (NPC) is one of the most common malignances in South China. Radiation therapy remains the principal treatment for NPC. The most frequently occurred radiation-related side effect is probably the radiation-induced oral mucositis (OM), which affects up to 100% of NPC patients receiving radiation therapy. Although intensity modulated radiation therapy (IMRT) has been widely used in China nowadays, the incidence of radiation-induced oral mucositis is still high. OM can decrease patients' oral intake and nutrition, leading to dehydration, weight loss, and declining performance status that may require intravenous fluid hydration, feeding tube placement, and hospitalization. OM also may increase opioid use. When severe, oral mucositis increases the risk of infection and may compromise clinical outcomes by necessitating treatment breaks, dosage reductions, and reduced therapy compliance. Common clinical management strategies include bland rinses, topical anesthetics and analgesics, mucosal coating agents, and systemic analgesics. However, none of these interventions has been supported by conclusive evidence. In China, a quadruple mixture, composed of dexamethasone, gentamicin, vitamin B12, and procaine, is commonly prescribed when NPC patients begin to suffer from radiation-induced OM.