The expression of transcription factor NF-κB (p50 and p65), ER, PR, Her2/neu, Ki-67, p53, Bcl-2 and E-cadherin in tumor tissue of 132 patients with breast cancer was investigated by immunohistochemistry. As a result of researches the correlation between Grade and expression of ER, PR, Bcl-2, Ki-67 and p65-subunit of NF-κB was defined. The level of proliferation was correlated with ER, PR, Bcl-2, p53 and Her2/neu expression. Also the correlation between some of investigated markers was found. Thus, high level of NF-κB nuclear expression was associated with Her2/neu hyperexpression and negative status of ER, PR and Bcl-2. These data may indicate poor prognosis and resistance to chemotherapy in breast cancer patients with activated NF-κB, but it requires further research and retrospective analysis of large number of patients.