<title>Abstract</title> <bold>Introduction</bold>: Neutrophil-to-lymphocyte ratio (NLR) is an inflammatory biomarker (hemogram-derived-ratio) related to ischemic-inflammatory diseases. Its usefulness in the diagnosis of pediatric testicular torsion (TT) has recently been reported, although its prognostic implication has not been evaluated. Our aim is to analyze the role of NLR in the evolution of TT in children, determining its potential for predicting the risk of adverse outcomes such as orchiectomy or testicular atrophy. <bold>Methods</bold>: We performed a retrospective multicentric case-control study in patients with clinical and ultrasound suspicion of TT, in whom surgical testicular examination was performed between 2016-2022 in seven pediatric hospitals. Patient’s outcomes were analyzed according to the intraoperative and postoperative evolution (orchiectomy/testicular atrophy or not). Demographics, clinical, ultrasound and laboratory features at admission were analyzed. Sensitivity and specificity were determined by the area under the curve (AUC) represented on the receiver operating characteristic (ROC) curves. <bold>Results</bold>: A total of 455 patients (median age 13.2 years; interquartile range 10.6-14.4 years) were included, in whom 87 orchiectomies (19.1%) were performed and 34 cases of testicular atrophy (7.5%) were observed during follow-up (median follow-up: 10 months). When comparing clinical, ultrasound and laboratory predictors of both events on ROC curves, NLR was the most sensitive and specific parameter for predicting orchiectomy (AUC=0.834; p&lt;0.001), as well as testicular atrophy (AUC=0.849; p&lt;0.001). Compared with other parameters, the designed cut-off point of NLR=5.2 had maximum sensitivity and specificity (82.2% and 77.0%, respectively) for predicting orchiectomy or atrophy after testicular torsion. <bold>Conclusion</bold>: NLR may be considered as the best predictor for the risk of orchiectomy or testicular atrophy following torsion in pediatric patients, helping the identification of high-risk cases. It can be useful both for obtaining more accurate preoperative information on patient prognosis and for closer follow-up of high-risk testicular atrophy patients.