Introduction: Urinary tract infection (UTI) is among the most prevalent bacterial infections in childhood and can result in permanent renal scarring and long-term kidney-related complications.
 This study aimed to evaluate the diagnostic value of urinary NGAL, KIM-1, C-reactive protein (CRP), and procalcitonin (PCT) for predicting renal scarring following UTI in children.
Methods: In This retrospective observational cross-sectional investigation, 182 pediatric patients with confirmed UTI were included. Demographic characteristics, ultrasonography, VCUG, DMSA scintigraphy findings, and biomarker levels were collected. Diagnostic performance was evaluated using ROC curve–based analysis, and independent predictors of renal scarring were identified using multivariable logistic regression.
Results: Participants had a mean age of 5.69 ± 3.49 years, and renal scarring was detected in 16 patients (8.8%).  Urinary NGAL concentrations were significantly elevated among patients with renal scarring compared with those without renal scars (p = 0.025). ROC curve analysis indicated moderate diagnostic accuracy for NGAL (AUC = 0.664, 95% CI: 0.535–0.793, p = 0.030). An optimal threshold of 213.9 ng/mL yielded a sensitivity of 87.5% and a specificity of 41.0%. In the multivariable logistic regression model, urinary NGAL remained the sole independent predictor of renal scarring (adjusted OR = 1.009, 95% CI: 1.001–1.017, p = 0.030).
Conclusion: Urinary NGAL was the only biomarker independently associated of renal scarring among children diagnosed with UTI. Although its diagnostic performance was only fair, urinary NGAL may act as a valuable complementary biomarker for identifying children who are at a higher risk of developing renal scarring and should be interpreted in conjunction with clinical and imaging findings.