BACKGROUND: Mucositis is a common and severe complication of anti-tumour therapy. The use of plant-derived drugs in patients with malignant neoplasms of the oral mucosa and maxillofacial area according to a certain group of dental risks shows good results and can be considered as one of the promising methods for the prevention and treatment of mucositis. One of the methods confirming the effectiveness of the local treatment is the determination of hemomicrocirculation in the tissues of the oral mucosa. OBJECTIVES: To determine the state of hemomicrocirculation in the tissues of oral mucosa in patients with oropharyngeal squamous cell carcinoma at different stages of anti-tumour therapy, as well as during the application of different methods for local treatment of oral mucositis. MATERIALS AND METHODS: From January 2017 to May 2018, in the Department of Radiotherapy of the National Medical Research Radiological Centre (NMRRC) of the Russian Federation, the microcirculatory parameter (MP) of hemomicrocirculation was determined in 69 patients diagnosed with oropharyngeal squamous cell carcinoma. RESULTS: In group I, hemomicrocirculation was higher at all measurement points than in group II. Clinical manifestations of oral mucositis in group I develop later than in group II and correspond to the maximum value of hemomicrocirculation in each group. CONCLUSIONS: The results confirm that the use of long-acting plant-derived drugs is more effective than traditional oral irrigation with chamomile decoction and oleotherapy for the prevention and treatment of oral mucositis: Decrease in microcirculation indicators of group I (using the drugs) is 7.4% less than one of group II (not using the drugs); p <0.04.