Introduction. Despite the large number of studies and clinical observations on timely analgesia in the postoperative period, there are no clearly formulated views on the nature of the pain syndrome, and there are no modern protocols for the treatment of pain after tonsillectomy. Purpose. The purpose of the study was to identify the effect of a homeopathic monocomponent herbal product Arnica Montana C9 (BUARON) on the condition of patients undergoing tonsillectomy. Materials and methods. The article presents a study that was conducted in patients with chronic decompensated tonsillitis who were admitted to the Department of Otorhinolaryngology, Pavlov First Saint Petersburg State Medical University for planned surgery. Results. Entered the results of the study into the developed computer database on a personal computer using tables «Microsoft Excel». Carried out the analysis and statistical processing of the obtained data using the software package Statistica for Windows v.10.0, determined the parameters of descriptive statistics. Discussion. In accordance with the results of statistical analysis, it was found that the use of a homeopathic monocomponent herbal product Arnica Montana C9 (BOIRON) in patients after tonsillectomy leads to a reduction in treatment time compared to traditional therapy. Conclusions. The use of Arnica Montana C9 (BOIRON) can reduce the severity of pain in patients after tonsillectomy.