OBJECTIVES: Although the discussion about oral mucositis in Head and Neck Cancer (HNC) patients has become a prominent issue, its incidence and influencing factors have not been thoroughly synthesized. This meta-analysis aims to integrate the prevalence and associated factors of radiation-induced oral mucositis among HNC patients. METHODS: This study searched the following electronic databases: PubMed, the Cochrane Database, the Web of Science, EMBASE, CNKI, the Wanfang Database, and the VIP Database. The publication timeframe for the included studies ranged from January 2005 until January 2024. Two investigators used the NOS scale and AHRQ evaluation criteria for quality evaluation. All qualified studies and statistical analyses were conducted using RevMan 5.2 and Stata 17.0. RESULTS: Thirty eligible studies were included in the analysis. The results show that the prevalence of radiation-induced oral mucositis in HNC patients was 94% [95% CI (89%, 98%)]. Furthermore, the prevalence of severe radiation-induced oral mucositis in HNC patients is 37% [95%CI (29%, 45%)]. Chemotherapy, smoking history, diabetes, oral PH ≤ 7.0, and alcohol consumption are the main risk factors for radioactive oral mucositis. In addition, BMI > 24.0 kg/m, no use of antibiotics, and no use of oral mucosal protective agents are associated with radioactive oral mucositis. CONCLUSIONS: This meta-analysis underscores a significantly high prevalence of radiation-induced oral mucositis in HNC patients. Establishing healthy lifestyle habits and maintaining a healthy oral environment are pivotal in preventing radiation-induced oral mucositis.