Introduction. Lymphangiomas are mature benign tumors emanating from the lymphatic vessels making up 9-10% of all benign neoplasms in pediatric oncology. In our practice, we have encountered a rare complication of the lymphangioma of the abdominal cavity - an ileus Objective: To present a clinical picture, diagnostic and surgical tactics in a rare clinical observation of mesenteric lymphangioma, complicated by ileus. Material and methods. Boy aged of 6 years 4 months. He was taken to the emergency department of the Research Institute of NDHiT by an ambulance team (SMP) with suspected acute appendicitis 6 hours after the onset of the disease. Results. According to the results of clinical, laboratory and echographic examination, a child with a clinical picture of “acute abdomen” was suspected of an abdominal lymphangioma. For the purpose of the differential diagnosis of a complicated course of the lymphangioma of the abdominal cavity with complicated destructive appendicitis, 2 hours after hospitalization, laparoscopy was performed and there was confirmed lymphangioma of the ileum mesentery, complicated by the twisting of the latter. After elimination of the torsion, a section of the ileum with a tumor was resected with an end-to-end anastomosis. Histologically, the diagnosis of lymphangioma was confirmed. Conclusion. The cause of “acute abdomen” may be the development of complications of the mesenteric lymphangioma. Timely hospitalization of the child in a specialized hospital allows making a diagnosis in a timely manner, select the optimal surgical tactics and prevent life-giving complications