Chronic kidney disease usually has no characteristic symptoms. The processes started in childhood often lead to end-stage renal failure in the future. Commonly used markers of renal function (creatinine, cystatin c, albuminuria, eGFR) do not have high sensitivity. Therefore, searching for candidates for an early, sensitive and specific biomarker became very popular. The tested new biomarkers may be more useful in the pediatric population than in adult patients, as children are usually not affected by other non-renal pathologies that may influence the results. There are several concepts of risk factors for chronic kidney disease: e.g. post-inflammatory scarring in renoscintigraphy and glomerular hyperfiltration. The aim of the study is the apraisal of the usefulness of new markers: KIM-1, FGF-23, NAG, NGAL, uromodulin in monitoring early stage of renal damage in children. 59 children (15 boys, 44 girls from 6 months to 17 years old) with kidney disorders, which had clinical indications for renoscintigraphy, were included in the study. The exclusion criteria were: elevated creatinine level, albuminuria, proteinuria, hypertension. Firstly, all patients were divided depending on the result of renoscintigraphy: the study group consisted of children with renal scarring, the control group consisted of children with normal kidney picture. Secondly, all patients were divided depending on the level of glomerular filtration calculated during isotopic scanning: the study group included children with glomerular hyperfiltration (>200ml/min), the control group included children with normal glomerular filtration rate. Concentration of KIM-1, FGF-23, NAG, NGAL in serum as well as concentration of NGAL and uromoduline in urine was measured in all patients. The results were compared in the above-mentioned groups. In children with renal glomerular hyperfiltration statistically significantly higher serum values of FGF-23 and NGAL were found in comparison to children with normal glomerular filtration rate (p<0,05). There were no statistically significant differences in serum concentrations of the tested markers in children with confirmed scars in the renal parenchyma in the renoscintigraphy compared to children with normal renal image. There were no statistically significant differences in concentration of tested markers in urine. The results of the study indicate the usefulness of FGF-23 and NGAL in monitoring the early stage of renal disease with glomerular hyperfiltration in children.