Background: There is a lack of uniformity with regard to the reporting terminology used in breast cytology by pathologists worldwide, resulting in miscommunication of results among health-care providers. Aim: The present study was aimed to assess the accuracy of fine-needle aspiration cytology (FNAC) in the evaluation of breast lesions using the National Cancer Institute (NCI) recommended terminology. Materials and Methods: In this prospective study, a total number of 523 breast FNACs were categorized according to the NCI guidelines. Of these, 286 (54.7%) had histopathological follow-up, and their FNAC diagnoses were compared. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) along with 95% confidence interval (95% CI) and accuracy of FNAC were calculated. Results: Among 286 FNAC cases, 4 were unsatisfactory (C1), 188 were benign (C2), 11 were atypical, probably benign (C3), 21 were suspicious, favor malignancy (C4), and 62 were malignant (C5). On histopathological examination of categories C2 and C3 (total of 199 cases), 193 were confirmed as benign (true negative) and remaining 6 cases were turned out to malignant (false negative). Among categories C4 and C5 (total of 83 cases), 81 were confirmed as malignant (true positive) and remaining 2 were turned out to be benign (false positive). The sensitivity, specificity, PPV, NPV, and accuracy of FNAC were 93.1% (95% CI, 88.2%–95%), 99% (95% CI, 96.8%–99.8%), 97.6% (95% CI, 92.5%–99.6%), 97% (95% CI, 94.9%–97.8%), and 97.2%, respectively. Conclusion: Our study concluded that FNAC reporting using NCI guidelines highly correlated with the histopathological diagnosis.