BACKGROUND Morphea, also known as localized scleroderma, is an autoimmune skin disease which is characterized by excessive accumulation of collagen that leads to the thickening of the dermis and subcutaneous tissue. There is an unclear relationship between morphea and other autoimmune diseases, especially related to the thyroid gland. OBJECTIVE To determine the occurrence of increased antithyroid antibodies in patients with morphea in relation to the clinical manifestations of the disease. METHODS Forty-two Caucasian patients with different forms of morphea were included into the study. To determine the thyroid status, thyrotropin (TSH), anti-peroxidase antibodies (TPO-Ab), anti-thyroglobulin antibodies (Tg-Ab) were evaluated with the use of the electrochemiluminescence method and TSH receptor autoantibodies (TRAb) - with the use of the radioimmunoassay method. RESULTS Increased levels of antithyroid antibodies were observed in 6 cases in relation to TPO-Ab (14.3%), in 4 cases in relation to of Tg-Ab (9.5%) and in 1 patient in relation to TRAb (2.3%). There was no difference in the level of antithyroid antibodies between circumscribed and generalized forms of morphea. CONCLUSIONS Although morphea is an autoimmune disease, it does not seem to be associated with increased prevalence of positive antithyroid antibodies. We conclude that there is no need to perform routine laboratory tests for thyroid disorders in patients with morphea.