Samples of blood serum originating from the patients with squamous cell carcinoma of various parts of the oral cavity (carcinoma planoepitheliale spinocellulare: mucosae buccae, fundi oris, linguae, palati molli) were analyzed for presence of some microelements (zinc, copper and iron) using the AAS method. The findings were compared to amounts of these elements in serum of healthy persons (control samples). Significant differences among groups (with cancer and control) were qualified using nonparametric U-Mann Whitney test. The mean contents of all the analyzed microelements in serum of persons with cancer were higher as compared with controls but statistically significant differences were only in case of copper and iron.