Oral recurrent aphthous stomatitis is the most common oral mucosal disease. Despite much clinical and research attention, the causes remain incompletely understood. Treatment options include no treatment, treatment of associated systemic diseases, topical medications, systemic treatment and palliative treatments. The most effective treatments involve agents that suppress or modulate the immune function. Topical agents are preferred due to its limited side-effects. Adjunct pain control and prevention of secondary infections is sometimes necessary.