Granulomatous mastitis is a chronic inflammatory disease of the breast with unknown etiology mostly seen in parous women shortly after their last pregnancy. It is crucial to differentiate granulomatous mastitis from cancer and definite diagnosis is established by histopathological examination. Its treatment is variable and the most appropriate treatment protocol is yet to be identified. Aim of the study was to compare the performances of fine needle aspiration and Core biopsy of breast lump verified by histopathological examination as “Gold standard”. 227 women presenting with breast lump were included in this study. After selection, fine needle aspiration and core biopsy were done at same sitting and follow-up resection histopathology with 122 cases (53.74%) were performed in the laboratory. 40(17.62%) cases were diagnosed granulomatous mastitis by either fine needle aspiration or core biopsy, the reports of 23 cases (57.5%) were concordant in both the procedures and discrepancy was observed in reporting of 17 cases (42.5%). 36 cases (90%) were resected for histopathology and 33 (82.5%) breast lumps were diagnosed granulomatous mastitis. Diagnostic accuracy, sensitivity, specificity, negative and positive predictive values of fine needle aspiration cytology and Core biopsy were calculated. The diagnostic accuracy of core biopsy was 97.54% and that of fine needle aspiration cytology was 89.34%. Specificity, sensitivity, positive and negative predictive values of core biopsy were 97.77%, 97.29%, 94.73% and 98.87% respectively. The specificity, sensitivity, positive and negative predictive values of fine needle aspiration were 97.77%, 70.27%, 92.85% and 88.88% respectively. The accuracy of core biopsy was much higher than that of fine needle aspiration and also the performances of the combination of two procedures were superior to the individual test alone.