Background: Appendicitis is a common diagnostic challenge in pediatric patients. Based on clinical and laboratory findings, the modified Alvarado scoring system (MAS) is commonly used to assess the likelihood of appendicitis. This study aims to evaluate the diagnostic performance of MAS compared to radiologic findings and its components in the diagnosis of appendicitis in children.Methods: This retrospective study involved 177 pediatric patients with abdominal pain. The MAS, radiologic examinations (ultrasound), and physical examination findings were evaluated. Data on MAS, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were analyzed. Chi-square tests were used to determine significant differences between MAS and radiologic findings.Results: The study included 92 males (52%) and 85 females (48%), with the majority (95, 53.7%) in the age group of 7-10 years. Of the 177 patients, 46 (26%) had positive radiologic findings for appendicitis. The MAS showed a sensitivity of 81%, a specificity of 69%, a PPV of 48%, and an NPV of 91%. A significant difference in the MAS was found between patients with positive and negative radiologic findings (p = 0.001). Compared with ultrasound, MAS showed a PPV of 39%, an NPV of 14%, a sensitivity of 48%, a specificity of 80%, an accuracy of 73%, and an odds ratio of 3.69. Rebound tenderness on physical examination also showed a significant association with appendicitis (p = 0.001).Conclusions: This study highlights the potential of the MAS as a valuable tool for the initial assessment of appendicitis in children, demonstrating high sensitivity and NPV. Although it has a moderate PPV and specificity, suggesting efficacy in ruling out appendicitis, it should be supplemented with radiologic findings for a definitive diagnosis. Tenderness remains a crucial clinical sign, emphasizing its importance on physical examination. These findings should guide future research to refine the MAS components and explore complementary diagnostic strategies to improve the accuracy of pediatric appendicitis diagnosis.