Background <p>The primary objective was to determine the sensitivity of acute renal angina index ≥ 8 in predicting the development of acute kidney injury&#xa0;(AKI) in critically ill children at 24&#xa0;h of admission in pediatric emergency. Our secondary objectives were to determine the sensitivity of acute renal angina index ≥ 8 in predicting AKI at 72&#xa0;h of admission in the above children and to determine the best cutoff of acute renal angina index for diagnosing AKI at 24 and 72&#xa0;h of admission.</p> Methods <p>This observational study included critically ill children between the ages of 1 and 12 who presented to pediatric emergency and were triaged as Level 1 or 2 using the Emergency Severity Index version 4.0. Acute renal angina index was calculated based on serum creatinine levels at admission. Urine output was monitored, and serum creatinine was repeated at 24 and 72&#xa0;h post-admission to assess for AKI in accordance with the Kidney Disease: Improving Global Outcomes guidelines.</p> Results <p>Out of 190 children enrolled in the study, 81 (42.6%) developed AKI. The acute renal angina index predicted AKI at both 24 and 72&#xa0;h of admission, with an area under the curve of 0.872 and 0.862, respectively. At 24&#xa0;h, the acute renal angina index ≥ 8 demonstrated a sensitivity of 85.19% and a specificity of 78.90%. At 72&#xa0;h, the sensitivity and specificity were 86.36% and 71.77%, respectively. The mean acute renal angina index score among AKI patients was 24.72 (17). Optimal cutoff values were identified as 8 at both 24&#xa0;h and 72&#xa0;h.</p> Conclusions <p>Acute renal angina index was found to be a useful marker for predicting AKI at 24 and 72 h of admission in critically ill children.</p> Graphical abstract <p></p>