Introduction. In the present trial, the authors studied anti-stress properties of subnarcotic concentrations of gas Xenon (Xe) which is used for treating children with severe traumas. Purpose. To study anti-stress properties of subnarcotic concentrations of gas Xenon (Xe) which is used for treating children with severe injuries. Material and methods. 10 children, aged 13 ± 3 years, with severe trauma were taken into the study: 6 girls with mine-explosive injuries ( a terrorist attack in Kerch in 2018), 3 boys with multiple dog bites and one patient after a traffic accident. To treat them, 20-30% Xe with O2 was used. A session lasted for 20 minutes; the course included from 5 to 12 sessions. Device KTK-01 (LLC “KseMed”, Russia) was used. Pain intensity was assessed with the numerical rating scale (NRS) , sedative effect - with BIS index and Ramsey sedation scale. Patients’ blood was also examined for the level of somatotropic hormone (STH), cortisol (Co) and insulin. Results. Indications for Xe therapy in children were: persistent pain syndrome (PS) and acute stress disorder (ASD). Patients fell asleep (drug-induced sleep) under 20-30% Xe concentration in the respiratory mixture. The average values of BIS index decreased from 95.5 ± 2.5 U to 86.5 ± 5.0 U (p <0.05), and of Ramsay scale - from 5.5 ± 0.5 to 2.7 ± 1.2 points (p <0.05). Pain intensity by NRS decreased from 4.1 ± 1.8 to 1.1 ± 0.4 points (p <0.05). The level of stress hormones during Xe session went down: STH- from 4.8 ± 0.9 ng / ml to 1.9 ± 0.5 ng / ml (p <0.001); Ko - from 375.5 ± 23.6 nmol / L to 303.2 ± 20.7 nmol / L (p <0.0001); insulin - from 19.9 ± 3.6 pmol / L to 11.7 ± 2.7 pmol / L (p <0.001). To restore sleep, 2 - 3 sessions were needed; to relief PS - 5 sessions, to refuse of painkillers in phantom pains - 12 sessions. Conclusion. 20-30% Xe with oxygen therapy has a pronounced analgesic, sedative and anti-stress effect in children with severe injuries.