BACKGROUND: Globally, breast cancer is the most common cancer in women. Natural Killer cells are one of the major components of the antitumor immune response. There is development of tumor specific T- cell responses to the parental tumour cells after the NK cell mediated elimination of tumor cells, thus serving as a link between innateand adaptive immune responses. Aim of the study role of natural killer cells in clinico-histological presentation of breast cancer. MATERIAL AND METHODS: 47 diagnosed cases of invasive duct carcinoma were selected as study cases that were diagnosed 24-48 months back from the initiating point of the study. By using immunohistochemistry, an anti- human CD56/NCAM-1 rabbit monoclonal antibody for CD56 Clone was used as a primary antibody, NK cells were counted and then compared with histological stage and grades of the tumor. RESULTS: Out of 47 cases, CD 56+ NK cell count by IHC was negative in majority of cases (27/47), followed by low count (12/47) and moderate count of IDC cases (8/47).Though negative and low NK cell expression could not correlate, however, moderate NK cell count was associated significantly with high histological grade (p=0.003) and stage(p=0.019). An inverse relationship was seen between low NK cell expression and axillary nodal status, but not so with moderate NK cell count. CONCLUSION: Knowledge about the role of NK cells, they home-less in breast carcinoma and the multifaceted immunosuppressive microenvironment blunts NK cell cytotoxicity, thus responsible for tumour progression. Study concentrates towards a possible immunotherapeutic solution of breast carcinoma in the form of reactivation of NK cells.