Acute kidney injury (AKI) is a common problem, especially in critically ill patients. In Critical Care, Kolhe and colleagues report that 6.3% of 276,731 patients in 170 intensive care units (ICUs) in the UK had evidence of severe AKI within the first 24 hours of admission to ICU. ICU and hospital mortality as well as length of stay in hospital were significantly increased. In light of this serious burden on individuals and the health system in general, the following commentary discusses the current state of knowledge of AKI in ICU and calls for more attention to preventive strategies.