Recurrent aphthous stomatitis (RAS) is a quite frequent, painful, ulcerative disease that affects the lining of the oral cavity and has an unknown etiology. The aim of this article is to examine the impact of the medication proaftol on epithelization speed and severity of pain in patients with RAS. In this randomized, double-blind, placebo-controlled study respondents were divided into two groups where one group was treated with proaftol spray and the other with a placebo. Aphthae considered for treatment had a diameter of 5-6 mm. The participants were given instruction on the use of the spray, two sprayings on the place of the aphtae 3-4 times a day. We examined two parameters in the symptomatology of RAS-lesion size (mm) and pain intensity (noted on four subjective levels: 0-no pain, 1-discomfort, 2-moderate pain, 3-severe pain). These parameters were noted on the baseline, the third, the fifth and the eighth days of examination. RESULTS A significant faster reduction of the dimension of aphthous ulcers in patients treated with proaftol 3rd day p<0.001, 5th day p<0.0006, 8th day full epithelization in the control group. The magnitude of pain in the experimental compared with the control group on 3rd, 5th and 8th day was also significantly reduced: p<0.0001, p<0.007, p<0.007 respectively. CONCLUSIONS The use of proaftol positively influences the rate of epithelization and reduction of subjective feeling of pain in patients with RAS. The action of propolis should be the goal of studies with a larger number of subjects.