The objective was to describe a case of cerebral edema (CE) in an adolescent patient with type 1 diabetes mellitus (DM) complicated with diabetic ketoacidosis (DKA), and to perform an analysis and review of publications devoted to this topic.Materials and methods. We describe the rare clinical case of CE complicated with DKA in the 14-year-old adolescent patient, including the dynamics of the patient’s clinical condition and laboratory test results. The topic of interest was researched through analysis of publications found in the Cochrane Library, PubMed, eLibrary.ru and Medscape databases using the following search terms: diabetic ketoacidosis, children and adolescents, cerebral edema, intensive therapy. A total of 38 publications in Russian and English were selected for being fully compliant with the purpose of this work. The features of the reported clinical case were analyzed and compared with information obtained from the current scientific literature.Results: This case demonstrates specific features presenting in the course of CE and describes aspects of the intensive treatment provided to the patient. Manifestations of severe hypokalemia and hypernatremia have been recorded as rare electrolyte disturbances in CE in the adolescent with DKA. The report demonstrates that the steps and specific parameters of the provided intensive treatment are unlikely to have triggered the development of CE in the clinic in this particular clinical case. It cannot be ruled out that the development of this complication was triggered by the delayed initiation of treatment (caused by the patient) at the prehospital stage, including the patient’s rude noncompliance with the prescribed insulin treatment scheme.Conclusions. CE is the rare but severe (with a high fatality rate) complication of DKA in patients with type 1 DM. Timely initiation of emergency care for CE may reduce risks associated with this complication and improve treatment outcomes and patient prognosis.