Abstract: Mucositis is a toxic side effect of anti-cancer treatments and is a major focus in cancer research. Pro-inflammatory cytokines have previously been implicated in the pathophysiology of chemotherapy-induced mucositis. The aim of this study was to detect a correlation between serum cytokine levels in head and neck (H and N) cancer patients receiving combined chemo-radiation therapy. Thirty patients with H and N epithelial cancer were recruited to this study. All patients received radiotherapy to the H and N region with doses ranging from 50-70 Gray (Gy). Chemotherapy with cisplatin, carboplatin, 5-fluorouracil and taxanes was given to high-risk patients, using standard chemotherapy protocols. Patients were evaluated for mucositis according to WHO common toxicity criteria and blood samples were drawn for inflammatory (IL-1 and TNF-a) and before and during treatment. The mucositis evaluation demonstrated mucositis grade IV in 33.3% of the patients after the 3rd treatment week. At the end of treatment, the number of patients with grade IV mucositis was less. IL-1 and TNF-α did not show any correlation with PEG tube installation. The level of cytokines measured before and during therapy showed decreased TNF-α especially after the third week of therapy. No relationship between IL-1 and TNF-α, level and mucositis grade was shown.