<h3>Introduction</h3> TGF-β and TNF-α are the main factors associated with the formation of fibrosis in most forms of chronic kidney disease (CKD). This study assesses the content of TNF-α and TGF-β in serum after the treatment of acute kidney injury (AKI) in children. <h3>Methods</h3> 50 children (aged 8 months-12 years) after AKI of various origins were assessed. After treatment 11 of them had satisfactory kidney function (Group 1), 39 were diagnosed with CKD: 19 - 1 stage (Group 2), 15 - 2 stage (Group 3) and 5 - 3 stage (Group 4). The Control group were healthy children. TNF-α and TGF-β were determined by ELISA. <h3>Results</h3> The TNF-α concentration in serum after the treatment of AKI in 1, 2, 3, 4 Groups of children was notsignificantly different (?>0.05). However, one year after AKI, a high level of TNF-α was associated with an increase in the percentage of patients with stages 2-3 of CKD (p<0.001). TGF-β concentration in serum was significantly (p?0.05) greater in all patients, but did not differ in patients of Groups 2, 3 and 4 (?>0.05). A high serum level of TGF-β (≥40.5 pg/ml) in the first 3 months after AKI treatment increases the risk of impaired kidney function (CKD stages 2-3). <h3>Conclusion</h3> These results confirmed that a high serum level of TGF-β in the first 3 months after AKI is a marker of possible fibrotic complications and a predictor of development of stage 2-3 CKD.