Cancer is a major global public health problem, with increasing incidence. When detected early, life-saving treatments can be applied. Radiotherapy eliminates malignant cells but damages healthy tissues. A common oral side effect is oral mucositis: inflammation, ulcers, pain, difficulty ingesting nutrients, treatment interruption. Propolis, a natural product from bees, has wound healing, anti-inflammatory, antibiotic, and antioxidant properties. Studies indicate its effectiveness against radiation-induced oral mucositis. The objective of the present work was to analyze the effect of propolis in the treatment of oral mucositis in patients undergoing radiotherapy, based on the critical review of clinical and review studies. A literature review study was conducted on scientific articles found in databases such as PubMed, Web of Science, and Scopus, in order to obtain information to support the use of propolis as a complement to conventional treatment of oral mucositis in patients undergoing radiotherapy. Numerous studies have demonstrated the effectiveness of propolis in treating oral mucositis, especially when applied directly to the mucosa. Additionally, its use has been proven safe and does not cause adverse effects in patients. It is evident that oral mucositis is a common side effect of radiotherapy, which can occur from the first week of treatment, causing pain, difficulty swallowing, and even interruption of cancer treatment. Propolis represents a promising therapeutic option to improve and delay the onset of this condition, enhancing the quality of life of patients