Aim: The aim of this study was to evaluate the diagnostic performance of the Thyroid Imaging Reporting and Data System (TI-RADS) classification in comparison to fine needle aspiration cytology (FNAC) for the diagnosis of thyroid nodules.Materials and Methods: This prospective study included 110 patients referred for thyroid nodule evaluation. All patients underwent high-resolution neck ultrasound with TI-RADS classification and FNAC. The TI-RADS classification categorized nodules from TR1 (benign) to TR5 (highly suspicious), while FNAC classified nodules as benign, malignant, suspicious for malignancy, or indeterminate. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated for both diagnostic tools. Statistical analysis was performed using SPSS version 21.0.Results: The study found that FNAC showed higher sensitivity (92.86%) compared to TI-RADS (85.71%), with FNAC also exhibiting higher specificity (95.71%) than TI-RADS (79.10%). FNAC had a higher accuracy (94.55%) than TI-RADS (83.64%). TI-RADS categories TR4 and TR5 were strongly associated with malignancy, showing significant p-values (0.0014 and 0.0020, respectively). FNAC outperformed TI-RADS in diagnosing both malignant and benign nodules, demonstrating its superior diagnostic reliability.Conclusion: FNAC is a more accurate and reliable method for diagnosing thyroid malignancies compared to TI-RADS, with higher sensitivity, specificity, and overall accuracy. However, TI-RADS remain an important tool for initial risk stratification of thyroid nodules. Combining both TI-RADS and FNAC improves diagnostic accuracy and minimizes the risk of misdiagnosis.