Objective of the Paper: To present a case of successful use of Peroral Endoscopic Myotomy (POEM) in oesophageal achalasia in a 6-year-old child at the Scientific and Research Institute of Emergency Paediatric Surgery and Traumatology. Key Points. Being highly efficient and minimally invasive, POEM has been gaining in popularity in management of oesophageal achalasia in adult patients. However, in paediatrics, clinicians remain wary of the method. POEM was used to treat grade 3 oesophageal achalasia in a 6-year-old girl. No intraoperative complications were recorded. The postoperative period was uncomplicated: feeding with strained food started the next day after surgery; the child was discharged from the hospital on day 3. During follow-up visits (3, 12, 24 months) the child did not have any complaints; symptoms of dysphagia regressed completely; 3-month weight gain was 4kg; endoscopic examination showed an unobstructed oesophagus without inflammation. Conclusion. POEM is a promising method for management of oesophageal achalasia in children; still, controlled randomised studies should be conducted in order to assess the efficiency of the method in comparison with the efficiency of laparoscopy and balloon dilatation. Keywords: endoscopy, children, oesophageal achalasia, peroral endoscopic myotomy.