The incidence of acute kidney injury (AKI) at neonatal intensive care units (NICU) is estimated as 6-24%. Traditional AKI markers i.e. serum creatinine (SCr) concentration, fractional sodium exertion, urine sodium concentration and renal failure index--are low sensitivity and low specificity markers but beside remain very late ones. Serum creatinine concentration arises 48 hours after renal tissue damage. The paper presents contemporary knowledge concerning concentration reference ranges of some early AKI biomarkers (NGAL, hKIM1, OPN, IL18)--either in term or preterm newborns. The most current reports about chosen AKI biomarkers in newborns with uncomplicated clinical course and in children with AKI within the course of sepsis or after cardiopulmonary bypass surgery--were discussed. Disposing of the reliable clinical data referring to early AKI biomarkers constitutes a valuable aid for clinicians who having got to know about the actual risk possess the time for proper clinical interventions.