SUMMARY
Introduction: Oral mucositis is a common and worrying clinical condition in patients undergoing radiotherapy of the head and neck regions and aggressive chemotherapy. Mucositis manifests as a continuous process, which begins with erythematous and atrophic lesions, which can progress to very painful ulcers. The immunopathogenesis of oral mucositis is considered a complex cascade of biological events, and advances in its understanding might result in promising and effective therapies. Objectives: The aim of this study is to highlight the recent findings of the immunopathogenesis of oral mucositis induced by chemotherapy and/or radiotherapy and their possible therapeutic agents. Methods and materials: scientific articles were selected in the PubMed and LILACS databases from December 2015 to May 2016, using the keywords in English "mucositis etiopathogenesis" and "mucositis". In PubMed 107 articles were found and, in LILACS, 61. The articles were selected after reading and those which reported detail on the immunopathology of oral mucositis were chosen. Results and conclusion: The literature indicates that histopathological changes related to oral mucositis, including apoptotic phenomenon, the action of certain chemical mediators and the influence of the oral cavity microbiota promote a better understanding of the immunopathogenesis of this type of injury and their biological development. Therefore, additional clinical studies based on scientific evidence are needed to get a better understanding of the immunopathology of oral mucositis and the determination of preventive agents and effective therapeutic for this deleterious effect arising from antineoplastic treatment.