Acute kidney injury is a clinical syndrome associated with increased patient morbidity and mortality, as well as serious short-term and long-term consequences, especially in the perioperative period. Yet, patients having suffering from temporary acute kidney injury and achieving full recovery of kidney function usually complain of poor quality of life associated with loss of energy and limited physical activity. Therefore, there is a necessity for a novel biomarker of acute kidney injury with better features than currently used serum creatinine and urine output. So far, several investigations have demonstrated that the fibroblast growth factor 23 could be that desperately searched novel biomarker of acute kidney injury. It cannot only detect kidney dysfunction at the time but also before the injury process begins. Moreover, serum levels of the fibroblast growth factor 23 can predict adverse progression of the kidney injury. However, the role of the fibroblast growth factor 23 in the acute but also in chronic kidney dysfunction is still a riddle that requires additional research to clarify it.