ABSTRACT Thyroid diseases are characterised by either excessive or insufficient secretion of thyroid hormones, with Hashimoto's thyroiditis (HT) being an example of insufficient hormone production. This autoimmune condition is marked by hypothyroidism and a high prevalence. The thyroid gland requires numerous trace elements for optimal hormone production and metabolic function. The present study aims to investigate the serum trace element and electrolyte profile in patients diagnosed with HT. For this purpose, serum was obtained from blood samples taken from adult patients diagnosed with HT (HT Group) and adult healthy controls (C Group) during routine controls. Serum (Se), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), potassium (K), calcium (Ca), and magnesium (Mg) levels were analysed by a method known as the potassium-inductively coupled plasma-optical emission spectroscopy (ICP-OES) method. The findings obtained were then subjected to statistical analysis using Student-t and Mann-Whitney U tests, following the implementation of normality control procedures. The results revealed that the HT group exhibited higher levels of Fe and Mn (p<0.01) compared to the C group. Additionally, lower levels of K, Ca, Mg, Cu (p<0.01, both), Se, and Zn (p<0.05, both) were observed in the HT group. In light of these findings, it can be concluded that there are trace element and electrolyte profile changes in HT patients.