Acute kidney injury (AKI) is a common and serious complication in patients in the Pediatric Intensive Care Unit (PICU). We conducted this study to estimate the incidence and the mortality rate of AKI in critically ill children as well as to describe some other related factors. A retrospective study was conducted at PICU of Queen Rania Abdulla Children Hospital, Amman, Jordan for the period extending from May 2011 to June 2013. The medical records of all patients admitted during this period, and their demographic data were reviewed. Patients with AKI were identified, and management and outcomes were reviewed and analyzed. AKI was evaluated according to modified RIFLE criteria. Of the 372 patients admitted to PICU, 64 (17.2%) patients developed AKI. Of these 64 patients who had AKI, 28 (43.7%) patients reached RIFLE max of risk, 21 (32.8%) patients reached injury, and 15 (23.4%) reached failure. Mean Pediatric Risk of Mortality II score at admission was significantly higher in patients with AKI than those without P <0.001. The age ranged between one month and 14 years with the median age as 5.4 year. Thirty-five (54.7%) were males. Sepsis was the most common cause of AKI. The mortality rate in critically ill children without AKI was 58.7%, whereas increased in children with AKI to 73.4%. The mortality rate in patients who received renal replacement therapy was 71.4% and was higher (81.5%) in patients who received mechanical ventilation (95%, [confidence interval (CI)] 79.3-83.4%) and was significantly higher in patients with multi-organ system dysfunction 90.3% (95%, [CI] 88.7-92.5%). The incidence of AKI in critically ill children is high and increased their mortality rate and higher mortality seen in the younger age group, especially those below one year. High mortality rate was associated with multi-organ system dysfunction and the need for mechanical ventilation.