Objective: The renal angina index (RAI) provides a clinically feasible and applicable tool to identify critically ill children at risk of severe acute kidney injury (AKI) in high-income countries. Our objective was to evaluate the performance of the RAI as a predictor of the development of AKI in children with sepsis in a middle-income country and its association with unfavorable outcomes.Methods: This is a retrospective cohort study in children with sepsis hospitalized in the pediatric intensive care unit (PICU) between January 2016 and January 2020. The RAI was calculated 12 hours after admission to predict the development of AKI and at 72 hours to explore its association with mortality, the need for renal support therapy, and PICU stay. Results:We included 209 PICU patients with sepsis with a median age of 23 months (interquartile range, 7-60). We found that 41.1% of the cases (86/209) developed de novo AKI on the third day of admission (KDIGO 1, 24.9%; KDIGO 2, 12.9%; and KDIGO 3, 3.3%).Overall mortality was 8.1% (17/209), higher in patients with AKI (7.7% vs 0.5%, P < 0.01). The RAI on admission was able to predict the presence of AKI on day 3 (area under the curve (AUC), 0.87; sensitivity, 94.2%; specificity, 100%; P < 0.01), with a negative predictive value greater than 95%. An RAI greater than 8 at 72 hours was associated with a greater risk of mortality (adjusted odds ratio [aOR], 2.6; 95% confidence interval [CI], 2.0-3.2; P < 0.01), a need for renal support therapy (aOR, 2.9; 95% CI, 2.3-3.6; P < 0.01), and a PICU stay of more than 10 days (aOR, 1.54; 95% CI, 1.1-2.1; P < 0.01). Conclusions:The RAI on the day of admission is a reliable and accurate tool for predicting the risk of developing AKI on day 3, in critically ill children with sepsis in a limited resource context. A score greater than eight 72 hours after admission is associated with a higher risk of death, the need for renal support therapy, and PICU stay.