Aim: The study aimed to assess the iodine status and maternal thyroid function in the pregnant women in Sivas that is a city in central Turkey. Material and Method: One hundred-ninety-three pregnant women in their second trimester who attended the hospital for routine antenatal care were included this study. Morning spot urine samples were collected in deiodized test tubes from the study population. Urine iodine levels were determined by colorimetric modified Sandell-Kolthoff reaction. Serum free triiodothyronine (fT3), free thyroxine (fT4) and thyrotropin (TSH) levels were measured by electrochemiluminescence immunoassays. Results: Median urine iodine levels were lower in Sarkisla, Susehri Gurun, Divrigi and Kangal than Sivas Center. Median urine iodine deficiency levels of pregnant women living in Sarkisla, Susehri Gurun, Divrigi and Kangal indicated mild iodine deficiency. Discussion: Iodine deficiency is a significant problem in Sivas. Therefore, there is need for a policy such as iodine prophylaxis for pregnant women living in Sivas to eliminate this problem.