Context: Recurrent aphthous ulcer (RAU) is an oral disease and the most common oral lesion, with 2% to 66% of the world’ s population infected annually. Its prevalence is about 25% in Tehran and 27. 6% in Mashhad. The etiology of RAU is multifactorial. Aphthous risk factors include: immunological factors, psychological factors, stress, trauma, sensitivity, family history, blood disorders, malnutrition, and use of certain medications, It should be noted that the best treatment for RAU is the topical application of drugs. The use of topical treatments is recommended not only because the drug can directly impact the source of the disease, but also systemic side effects of the drug are reduced. Treatment of RAU has been considered in Iranian traditional medicine (ITM), and is covered in therapeutic books. The use of herbs in RAU has a centuries-old history; accordingly, extensive research should be conducted for this treatment of the disease. Evidence Acquisition: Iranian medical sources were reviewed and effective plants used in the traditional treatment of RAU were found and compared with new findings. Finally, we have created a table listing the plants that are part of the therapeutic protocol for RAU. Results: Based on this article we can explain some of traditional pharmacological effects of plants and how these plants can be a source for a cure. Conclusions: The plants listed can be used as a prediction of RAU management. Of course, there are is no evidence for curing RAU by some of these plants in allopathic medicine, and the further investigations in this area could lead to the discovery of a new drug.