<p>Neonatal acute kidney injury (AKI) affects approximately one third of newborns admitted to neonatal intensive care units and is associated with increased morbidity and mortality. The etiology of neonatal AKI is multifactorial, with prematurity and low birth weight being major risk factors. Diagnosis can be challenging, as current criteria rely on serum creatinine and urine output which have considerable limitations. The need for a timely and correct detection of AKI has led to the search for biomarkers, such as neutrophil gelatinase-associated lipocalin, cystatin C, kidney injury molecule-1 and interleukin-18, which have yet to be implemented in current clinical practice. Fluid accumulation is associated with poor outcomes and has been challenging to identify in neonates. New techniques, such as bioeletrical impedance analysis and point of care ultrasound, have just started being used in the pediatric population, and may be of interest in neonates, as well. Several studies have shown that neonatal AKI can have long term consequences and manifest as chronic kidney disease in children and adults, and therefore should warrant close monitoring and adequate follow up.</p> Graphical abstract <p></p>