Background: Nasopharynx carcinoma is the most common malignant tumour in head and neck region. Radiotherapy is the first choice of treatment for nasopharynx carcinoma that had not been metastases. The most common oral complications in radiotherapy is mucositis (± 80%). 0.15% benzydamine hydrochloride (HCl) oral rinse can be used to prevent radiation-induced oral mucositis. Purpose: The aim of …