This prospective observational study of 126 patients with right iliac fossa pain suspected of acute appendicitis compared the Appendicitis Inflammatory Response (AIR) scoring system against contrast-enhanced computed tomography (CECT) and ultrasound (USG) abdomen. Patients underwent emergency open appendicectomy and were evaluated preoperatively using these methods, then compared with postoperative histopathological diagnosis. The AIR score showed a high positive rate (92%) similar to CECT (92.85%), but higher than USG (78.57%). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were notably higher for CECT abdomen and AIR score compared to USG. CECT demonstrated the highest accuracy (96.03%) and diagnostic effectiveness. The study concludes that CECT is the most effective diagnostic tool for acute appendicitis, but in the absence of CECT facilities, the AIR score is a viable alternative, outperforming USG in accuracy, specificity, and diagnostic value. This finding supports the AIR score as a reliable tool for acute appendicitis diagnosis in settings lacking advanced imaging resources.