Background. The development and progression of head and neck malignancies is closely related to the expression of transcriptional and growth factors. One of them is the nuclear transcription factor NF-kB, which plays an important role in inflammation and carcinogenesis. This factor regulates a large number of genes involved in the formation of inflammation and carcinogenesis, including the resistance of tumors to chemoradiation therapy. NF-kB inhibitors can alter its expression and thereby affect tumor progression, so NF-kB may be a marker of disease prognosis and a promising target for modern targeted therapy in patients with HNSCC. Purpose – to determine the level of NF-kB in the blood serum of patients with HNSCC and to evaluate the relationship of this indicator with the main clinical and morphological characteristics of the disease. Materials and methods. We examined 25 patients with HNSCC and 10 patients without cancer. A general clinical examination of all patients was performed, and a biopsy morphologically confirmed squamous cell carcinoma according to the histological classification. Patients of stages I–IV were included in the study. NF-kB1 (p105 → p50) and VEGF levels were determined in the serum of patients with HNSCC by ELISA using standard reagent kits. The measurements were performed using a semi-automatic enzyme-linked immunosorbent assay analyzer «Immunochem-2100» (USA). To determine the content of NF-kB and VEGF, blood samples were taken from patients before radiation treatment. Results. It has been shown that the level of NF-kB in patients with HNSCC before treatment was 4.8 times higher (p < 0.05) compared with the level of this indicator in healthy subjects (median – 8.59 ng/ml vs. 1.79 ng/ml). It was noted that the level of NF-kB in patients with stage III–IV was 2.3 (p < 0.05) times higher than in patients with stage I–II. It was determined that the content of NF-kB in patients with HNSCC with lymph node involvement (N+) was 3.4 times higher than in patients without lesions (p < 0.05). It was found that the highest level of transcription factor was observed in tumors of the oral cavity. The level of NF-kB in the blood serum of patients with HNSCC correlated with the level of VEGF. In 88% of patients, the NF-kB factor was increased by 5.5 times compared to the control group. Thus, the analysis of the content of nuclear transcription factor NF-kB in the blood serum of patients with head and neck cancer before antitumor treatment makes it possible to predict the radioresistance of the tumor and further choice of radiation treatment tactics. Conclusions. It has been shown that the level of NF-kB in patients with HNSCC before special treatment was significantly higher compared to the level in healthy subjects. The dependence of NF-kB expression before special treatment on the stage of the disease, lymph node involvement, and tumor localization was determined. It was proved that in 88% of cases, increased levels of the transcription factor NF-kB correlate with increased levels of VEGF. The highest value of NF-kB is observed in patients with HNSCC aged 50–70 years, no dependence on the sex of patients was noted.