Acute kidney injury (AKI) is one of the most common and morbid complications of decompensated cirrhosis. Management of AKI is dictated by cause: prerenal AKI is treated with volume resuscitation; hepatorenal syndrome (HRS), with intravenous albumin and vasoconstrictors; and acute tubular necrosis, with supportive care. However, differentiating between causes is difficult using creatinine-based definitions of AKI alone. The use of novel kidney biomarkers in AKI and cirrhosis provides an opportunity to improve both the diagnosis and prognosis of this vulnerable population.