Breast carcinoma is the most common cause of mortality and morbidity among women and a lump in the breast is the most common presenting complaint. It is essential to correctly diagnose this condition to prevent misdiagnosis of cancer. The role of Fine needle aspiration cytology (FNAC) and Core needle biopsy (CNB)/Trucut biopsy of breast lumps is to rule out and diagnose cancer accurately and to obtain tissue for analysis. We performed a prospective study on 50 patients to compare the diagnostic efficacy of FNAC and CNB with final histopathological report of excised specimen as a gold standard for diagnosis. Patients underwent all three procedures namely FNAC, CNB, and surgery. Staining of cytology smears was done using Haematoxylin and Eosin (H&E), May-Grunwald-Giemsa (MGG) and Papanicolaou (Pap) stains. For CNB and tissue specimens obtained from excisional surgeries, Haematoxylin and Eosin (H&E) stain was used. In diagnosing breast carcinoma, FNAC depicted sensitivity of 70.8%, specificity of 96.2%, positive predictive value (PPV) of 94.4%, negative predictive value (NPV) of 78.1%, and diagnostic accuracy as 84% whereas CNB showed similar values as 87.5%, 100%, 100%, 89.7%, and 94% respectively. Our study concluded that CNB had higher sensitivity, specificity, PPV, NPV, and diagnostic accuracy than FNAC and therefore is more accurate than FNAC in diagnosing breast carcinoma. But in centers where facilities and equipment are still not available for CNB, FNAC is still useful as an initial investigation as it is a simple, rapid, and economical method requiring less expertise.