The present study was conducted to evaluate the serum copper, zinc, magnesium, and selenium levels in patients with subclinical hypothyroidism in the iodine-rich region of Ankara, Turkey. The effects of hormone replacement therapy on these elements were also studied in these patients. Basal levels of selenium and iron in patients were significantly lower than control group (67.7 +/- 10.4 vs. 83.7 +/- 17.3 microg/dl, p = 0.02; 55.7 +/- 38 vs 275.7 +/- 24, P = 0.03 microg/dl). Serum magnesium levels were significantly higher in patient group (2.16 +/- 0.31 vs 1.95 +/- 0.13 mg/dl, P < 0.0001). There was a correlation between selenium levels with hsCRP (r = -0.408, p = 0.007). HsCRP levels in patients with selenium levels <80 microg/l (n = 31) was significantly higher than hsCRP levels in patients with selenium levels >80 microg/l (n = 12; 1.99 +/- 1.0; 1.02 +/- 0.9, p = 0.014). None of these biochemical risk factors and trace elements have changed after euthyroidism in patients with SH when compared to pretreatment levels. Selenium deficiency may contribute to cardiovascular disease risk in these patients.