Introduction. In this study we aimed to evaluate urinary iodine excretion and the serum levels of thyroidstimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4) and thyroglobulin (Tg) in pregnants and their newborn infants. Materials and Methods. This study was performed in Konya Faruk Sukan Children and Maternity Hospital, Konya Beyhekim State Hospital and Hospital of Selcuk University Medical Faculty. 180 pregnant women and their healthy infants born at 37-40 gestational weeks.Term infants included in this study were aged between 1-7 days, healthy. Midurination urine samples were taken into deiodinized plastic bottles and 2 mL of these samples were aliquoted to deiodinized eppendorf tubes. Results. Median urinary iodine concentration (UIC) was 95.5 µg/L for pregnant women and 245 µg/L for their infants. Frequency of iodine deficiency was observed as 63.3% (n=114) (<150 µg/L) and 24.4% (n=44) (<100 µg/L) in mothers and their infants, respectively. UIC of the infants whose mothers used iodized salt was significantly higher than the one whose mothers used rocksalt (p=0.030). Conclusions. It was stated in our study that UIC of pregnants was lower than the target limit (<150 µg/L), suggested by World Health Organisation (WHO) and iodine deficiency in pregnants is still a problem in our city located in the centre of Turkey. Iodine deficiency was observed in 24.4% of the infants and this prevalence suggests us that iodine deficiency is still an important health problem in infants.