Background: Acute kidney injury (AKI) biomarkers are often susceptible to confounding factors, limiting their utility as a specific biomarker, in the prediction of AKI, especially in heterogeneous population. The urinary CXC motif chemokine 10 (uCXCL10), as an inflammatory mediator, has been proposed to be a biomarker for AKI in a specific setting. Whether uCXCL10 is associated with AKI and predicts AKI in critically ill patients remains unclear. The aims of the study were to investigate clinical variables potentially associated with uCXCL10 levels and determine the associations of uCXCL10 with AKI, sepsis and PICU mortality in critically ill children, as well as its predictive values of aforementioned issues. Methods: Urinary CXCL10 levels were serially measured in a heterogeneous group of children during the first week after pediatric intensive care unit (PICU) admission. AKI diagnosis was based on the criteria of Kidney Disease: Improving Global Outcomes with serum creatinine and urine output. Sepsis was diagnosed according to surviving sepsis campaign international guidelines for children. Mortality was defined as all-cause death occurring during the PICU stay.Results: Among 342 critically ill children, 52 (15.2%) developed AKI during the first week after PICU admission, and 132 (38.6%) were diagnosed as sepsis and 30 (12.3%) died during PICU stay. Both the initial and peak values of uCXCL10 remained independently associated with AKI with adjusted odds ratios (AORs) of 1.791 (P = 0.010) and 2.002 (P = 0.002), sepsis with AORs of 1.679 (P = 0.003) and 1.752 (P = 0.002), septic AKI with AORs of 3.281 (P <0.001) and 3.172 (P <0.001), and PICU mortality with AORs of 2.779 (P = 0.001) and 3.965 (P <0.001), respectively. The AUCs of the initial uCXCL10 for predicting AKI, sepsis, septic AKI, and PICU mortality were 0.63 (0.53-0.72), 0.62 (0.56-0.68), 0.75 (0.64-0.87), and 0.77 (0.68-0.86), respectively. The AUCs for prediction by using peak uCXCL10 were as follows: AKI 0.65 (0.56-0.75), sepsis 0.63 (0.57-0.69), septic AKI 0.76 (0.65-0.87), and PICU mortality 0.84 (0.76-0.91).Conclusions: Urinary CXCL10 is independently associated with AKI and sepsis, and may be a potential indicator of septic AKI and PICU mortality in critically ill children.