Thyroid adenomas (TA) are benign tumors, but there is a 20% possibility of malignant transformation. The distinguishing between the TA and thyroid cancer (TC) is tricky, therefore new TA biomarkers are needed. Furthermore, the role of trace elements (TE) in etiology and pathogenesis of TA is unclear. The aim of this exploratory study was to examine the content of ten trace elements (TE): silver (Ag), cobalt (Co), chromium (Cr), iron (Fe), mercury (Hg), rubidium (Rb), antimony (Sb), scandium (Sc), selenium (Se), and zinc (Zn) in the normal and adenomatous thyroid. Thyroid tissue levels of TE were prospectively evaluated in 46 patients with TA and 105 healthy inhabitants. Measurements were performed using non-destructive instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides. Tissue samples were divided into two portions. One was used for morphological study while the other was intended for TE analysis. It was found that in adenomatous thyroid content of Ag, Cr, Hg, and Zn were significantly higher than in normal gland tissues. Thus, it is possible to suppose that the considerable changes in TE contents in the adenomatous transformed tissue of thyroid can be used as TA biomarkers.