Background: Development of large-scale sequencing efforts of cancer genomes has led to identification of newer therapeutic targets. Nuclear Factor- kappaB (NF-kB) is one such promising transcription factor and is the subject of much active research as a target for anti- breast cancer therapy. This study was conducted to study the expression patterns of NF-kB in breast cancer and to correlate the findings with the histopathological grade of the tumours. Methods: This study was carried out on 25 samples of breast carcinomas.NF-kB was demonstrated immunohistochemically in the malignant epithelial cells of the tissue samples by using ImmPRESS polymerized reporter enzyme staining system which has been shown to have very good sensitivity and signal intensity, low background staining and reduced non- specific binding .This system is based on a new method of polymerizing enzymes and attaching these polymers to antibodies. The specimen was considered to be positive if more than 10% of tumour cells stained. The distribution of staining in the tumour cells was graded as 1= focal (<10%), 2= regional (11–50%), or 3= diffuse (>50%). Results: Among the 25 cases invasive ductal carcinoma, 12 (48%) cases showed immunoreactivity for NF-kB. 67% (8/12) of the cases showed both nuclear and cytoplasmic positivity.7 cases belonged to grade I, 10 cases to grade II and 8 cases to grade III. Conclusion: NF-kB is frequently overexpressed in primary breast cancer and showed increasing trends in tumours of grades I and II. However, discrepancies were seen with grade III tumours. As a result of their widespread expressions in different tumours, and generally low-level expression in normal tissue, NF-kB can be considered to be the prospective newer adjuvant target for apoptosis-based chemotherapy. Further studies need to be carried out to investigate the contribution of this protein to various cancer phenotypes and to be used as a potential molecular target for their treatment.