Background and Objective: Minor aphta has a high incidence in the populations ranging from 2-50%. In spite of its frequency and severity of discomfort, there is not an absolute treatment for it. So, the main objective of this study was to evaluate the efficacy of a herbal medicine in the control of Minor aphta.   
Materials and Methods: In this double-blind, randomized study 137 patients with Minor aphta (with not more than four days from the onset) were selected and then placed into one of the groups of A (solution containing 5 percent Myrtus communis and Melissa officinalis in ethanol 80) and B (solution containing 10 percent Myrtus communis and Melissa officinalis in ethanol 80) or C (placebo containing ethanol 80).
Results: Mean duration for complete recovery in minor aphta was 3/5 days in group A, 7/5 days in group B and 7/3 days in group C. These results showed a significant statistical differences in the three groups
(p<0/0005).
Conclusion: The results of this study revealed that using a combination of Myrtus Communis and Melissa Officinalis plants was effective in the treatment of RAS. In order to obtain the accurate concentrations of the ingredients of this compound, further studies are necessary.