Objective Pediatric ovarian torsion is a rare but serious condition that requires prompt diagnosis to prevent ovarian damage. This study evaluated the predictive value and reliability of specific sonographic signs in diagnosing pediatric primary ovarian torsion and correlated these findings with surgical outcomes. Materials and methods This retrospective multicenter study analyzed ultrasound and surgical records from 103 girls aged 7–14 diagnosed with suspected ovarian torsion across three institutions from November 2021 to June 2024. Three senior radiologists independently reviewed ultrasound findings, and surgical records served as the reference standard. Diagnostic performance was calculated for each ultrasound sign, both individually and in combination. Univariate and multivariate logistic regression analyses were performed to assess the predictive value of these signs. The inter-reviewer agreement (IRA) among three radiologists was also evaluated using Fleiss kappa statistics. Results Ovarian torsion was confirmed in 87 out of 103 cases (84.5 %). The most predictive sonographic signs were ovarian enlargement (OR = 10.09, 95 %CI: 2.01–50.57, p < 0.005), abnormal ovarian position (OR = 8.65, 95 %CI: 1.89–39.52, p < 0.005), and abnormal blood flow (OR = 5.61, 95 %CI: 1.12–28.17, p = 0.036). Ovarian enlargement had the highest sensitivity (92 %), while follicular ring sign showed perfect specificity (100 %). The combination of abnormal ovarian position and enlargement yielded a high positive predictive value (98.6 %). The IRA was excellent for ovarian enlargement (κ = 0.90) and abnormal position (κ = 0.85). Conclusion Ovarian enlargement, abnormal ovarian position, and abnormal blood flow are reliable predictors of pediatric ovarian torsion on ultrasound. Combining these signs improves diagnostic accuracy and can guide timely surgical intervention.