With the ageing of the population, improvements in health promotion and the intense process of urbanization, infectious diseases have been replaced by diseases such as malignant neoplasms. As a treatment for malignant neoplasms, antineoplastic chemotherapy is still a widely used form of treatment, generally causing a range of unpleasant side effects, such as oral mucositis. The content of this book deals with the production of a protocol for the prevention and treatment of oral mucositis with the aim of contributing to a higher quality of care, reducing the institution's costs, and standardizing the actions of the multi-professional team during the period of treatment of the cancer client undergoing antineoplastic chemotherapy.