Background: International Academy of Cytology (IAC) Yokohama System has developed a standardized system of reporting breast cytology, It has 5 categories that may be stratified by their risk of malignancy (ROM) and supply guidance within a management algorithm for every category. The main objectives were to categorize the Breast FNAC samples according to new system of reporting and to assess the Risk of malignancy (ROM) and diagnostic accuracy for all categories. Materials and Methods: A total of 212 Breast FNAC were done & retrospectively studied over a period of one year from 1st November 2021 to 31st October 2022 in Department of Pathology GajraRaja Medical College, Gwalior M.P. All the FNAC received was reported routinely according to the newly proposed Yokohama system of reporting breast cytology. Out of these 212 cases 72 were correlated histopathologically. The Risk of Malignancy and diagnostic accuracy of Breast FNAC were calculated. Results: ROM is 0% for category 1, 2.5% for category 2, 16.6% for category 3, 77.7% for category 4 and 100% for category 5. Diagnostic accuracy were 0% for category 1, 97.5% for category 2, 83.3% for category 3, 77.7% for category 4 and 100% for category 5. Conclusion: Categorization of the Breast FNA cytology according to IAC Yokohama system of reporting helps pathologist in the diagnostic clarity and guides clinician in the appropriate patient management.