This issue of Critical Care Clinics, guest edited by Drs. John Kellum and Dana Fuhrman, focuses on Acute Kidney Injury. This is one of four issues each year selected by the series consulting editor, Dr. John Kellum.　 Articles in this issue include, but are not limited to: Acute Kidney Injury and Disease, AKI in Cardiac Surgery, AKI in Sepsis, Hepatorenal Disease, Cardiorenal Syndrome, Onconephrology, Renal Functional Reserve and more.