Oral mucositis, which refers to erythematous and painful ulcerative lesions of the oral mucosa, is one of the most common adverse events associated with cancer therapies in the pediatric population. Although the pharmacologic and supportive therapy management of cancer treatment has advanced, the mucositis frequency is still increasing. Different methods and therapeutic agents are used in the prevention and treatment of oral mucositis, including basic oral care protocol, antimicrobial agents, cryotherapy, antiseptic agents, antibiotics, vitamins, cytokines, immune regulators, and herbal methods. Non-medical mouthwashes are recommended in basic oral care protocols. There is no conclusive evidence that mouthwashes contain chlorhexidine, normal saline, sodium bicarbonate, and benzydamine to prevent oral mucositis. Vitamin E can be an effective treatment method in reducing the severity of oral mucositis. Cryotherapy is a preferable treatment method according to the degree of mucositis in cooperative children receiving chemotherapy. There are different results in the literature regarding using chlorhexidine, laser therapy, and glutamine in children. It is recommended to avoid its use until its efficacy is demonstrated in systematic reviews and meta-analysis studies for its use in pediatric oncology patients. This review aims to evaluate the recommended and not recommended agents and practices in the prevention and treatment of oral mucositis in pediatric oncological patients receiving chemotherapy.