Introduction. Severe injury is referred to as types of child injury with a high mortality rate. One of the causes of fatal outcomes is bleeding from acute ulcers of the gastrointestinal tract. Bleeding from acute ulcers of the upper gastrointestinal tract is considered to be both not only the cause of deaths and also a factor in secondary hypoxic damage to organs and systems, leading to a complicated course of the post-traumatic period. Aim of the study. To substantiate the protocol of endoscopic monitoring of the state of the upper GI tract in the critical period of severe trauma in children. Material and Methods. 124 children aged from 0 to 18 years were examined. The severity of injury according to an ISS scale was 27.5 ± 10.1 scores. All patients were divided into 6 groups on the basis of leading damage. Esophagogastroduodenoscopy with the examination of the initial segments of the jejunum was performed on the 7-10th day of the post-traumatic period. In children with a severe spinal injury, esophagogastroduodenoscopy was performed on the 1-2nd day. The presence of pathological impurities, the condition of the mucous membrane, and peristaltic activity was evaluated. In the diagnosis of bleeding, combined endoscopic hemostasis was performed. Results. Erosions and ulcers were identified as the main endoscopic pathology in groups of children with leading skeletal and abdominal trauma, as well as with combined trauma with competing injuries. The group with abdominal trauma was leading in the number of gastrointestinal bleeding. Conclusion. Destructive changes in the upper GI tract are typical for the critical period of severe injury. It determines the mandatory planned conduct of esophagogastroduodenoscopy in the monitoring mode.