Outcomes in critically ill neonates have improved over the past three decades, yet high residual mortality and morbidity rates exist. Acute kidney injury (AKI) is not just an innocent by-stander in the critically ill patient. Research on incidence and outcomes of AKI in the critically ill neonatal population is scarce. The objective of this publication is to (a) review original articles on the short- and long-term outcomes after neonatal AKI, (b) highlight key articles on adults and children with AKI in order to demonstrate how such insights might be applied to neonates, and (c) suggest clinical research studies to fill the gaps in our understanding of neonatal AKI. To date, observational studies suggest high rates of AKI and poor outcomes in critically ill neonates. Neonates with AKI are at risk of developing chronic kidney disease and hypertension. Large prospective studies are needed to test definitions and to better understand risk factors, incidence, independent outcomes, and mechanisms that lead to poor short- and long-term outcomes. Early biomarkers of AKI need to be explored in critically ill neonates. Infants with AKI need to be followed for sequelae after AKI. © IPNA 2008.