The purpose of this study was to assess the thyroid and iron status of pregnant women on the basis of biochemical indicators and to look for correlation dependences amongst them. A subject of this research were 128 pregnant women from Plovdiv, Southern Bulgaria. For the assessment of the iron status the following indicators were examined: hemoglobin (Hb), serum ferritin (SF), soluble transferrin receptors (sTfR), Body iron(mg/kg), defined by the formula:-[log(sTfR/SF)-2.8229]/0.1207. To assess the thyroid status the urinary iodine concentration was examined, and also the thyroid stimulating hormone (TSH) and free T4 (FT4). The results demonstrated that more than 1/3 of the examined pregnant women had Hb<110 g/L, and 69% had SF less than 15 g/L, which is indicative for iron deficiency, 18.5% were with Body iron<0 mg/kg (indicate tissue iron deficiency). During the assessment of the thyroid status on the basis of ioduria it turned out that more than half of the pregnant women (59.3%) had iodine deficiency, 5.8% and respectively 19.0% had deviation in the values of TSH and FT4. In conclusion we can summarize that we have found out significant associations between iron deficiency with pregnant women and deviations in their thyroid status, which provides us with a solid base to continue and deepen the research in this direction.