Aim. To improve methods of diagnostic and treatment of acute kidney failure in children depending on the etiology factor of the disease. Material and methods. The results of the complex diagnostic and treatment of 144 children with acute kidney failure were analyzed. The main researched group included 60, 4% of boys. Patients received standard clinical laboratory and instrumental examinations. Analysis of the laboratory indicator was conducted at admission and after the extracorporeal detoxication. Results and discussion. The result of conducted research shows, that one of the leading mechanisms of acute kidney failure in children is a prerenal mechanism that was observed in 79 (55%) patients. Complex and intensive treatment (detoxication, enterosorption, correction of metabolic disorders, modern surgical manipulations) of patients with acute prerenal kidney failure decreased mortality by as much as 24%, 19 lethal outcomes out of 79 cases. Conclusion. Timely conduction of clinical laboratory and instrumental examinations using modern technologies is a ground for early diagnosis of acute kidney failure.