BACKGROUND Fine needle aspiration cytology (FNAC) has become the standard primary diagnostic method in carcinoma breast. It is also a useful tool for surgical treatment and prognosis. The present study is designed to correlate cytological grading using Mouriquand’s grading method with histological grading using modified Bloom-Richardson grading method. METHODS This was an observational study. A total of 45 cases of breast carcinoma, aged 30 to 80 years, underwent FNAC and the smears were graded using Mouriquand’s criteria. All the cases were correlated with Bloom-Richardson grade on histopathology in mastectomy specimens. RESULTS There were a total of 44 cases of infiltrating ductal carcinoma and 1 case of mucinous carcinoma on cytology. Patients’ age ranged from 30 to 80 years with a mean of 53.27 years. In terms of cytology, 15 were (33.3 %) grade I cases, 27 (60 %) grade II and 3 (6.7 %) grade III. In histopathology, 19 (42.2 %) were grade I, 21 (46.7 %) were grade II and 5 (11.1 %) were grade III. Grade I showed a sensitivity of 52.6 % and specificity of 84.6 % with positive predictive value of 71.4 % and negative predictive value of 71 %. Grade II showed a sensitivity of 76.2 % and specificity of 50.0 % with positive predictive value of 57.1 % and negative predictive value of 70.6 %. Grade III showed a sensitivity of 20 % and specificity of 95 % with positive predictive value of 33.3 % and negative predictive value of 90.5 %. Concordance rate between cytology and histology of grade I, grade II and grade III tumours was 73.3 %, 59.25 % and 33.3 % respectively. The absolute concordance rate was 62.2 %. CONCLUSIONS Thus, cytological grading of breast carcinoma correlates well with histopathological grading. In the era of multiple treatment modalities and neoadjuvant therapy, cytological grading can be used as a prognostic factor for better management of patients. KEYWORDS Breast Carcinoma, Mouriquand’s Grading, Bloom-Richardson Grading