Anemia during pregnancy is a risk factor of disturbance in pre- and postnatal child's development. Hepcidin plays the key role in iron metabolism, as protein participating in the regulation of intestinal absorption of this element and its release from macrophages, and transport across the placenta. Maternal smoking during pregnancy can result in disturbances of iron homeostasis leading to a subclinical deficiency. The depletion of maternal iron can cause fetal hypoxia condition and decreased expression of hepcidin. The aim of the study was to evaluate the effect of smoking on the levels of hepcidin and erythropoietin (as an indicator of hypoxia) and their relationships in umbilical cord blood. The research material was the umbilical cord blood of 50 newborns born in the Department of Obstetrics and Gynecology (Institute of Mother and Child in Warsaw) in the years 2013-2014. Based on an interview and determination of cotinine in the blood of mothers, newborns were divided into following groups: children of smoking mothers (n=20) and children of tobacco abstinent mothers (n=30). Hepcidin and erythropoietin concentrations were determined by enzyme immunoassay using commercial kits (DRG, Germany). It has been shown that hepcidin concentrations were significantly lower in children of smoking mothers than in the group of tobacco abstinent (37.5 ng/mL vs 45.1 ng/mL, p<0.001). However, the level of erythropoietin was higher in children of smoking mothers than in children of non-smoking women (p<0.001). A negative correlation between the levels of hepcidin and erythropoietin (r = -0.41, p<0.05) and number of smoked cigarettes (r = -0.43, p<0.05) was observed. These results indicate that smoking during pregnancy significantly affects hepcidin levels in children born at term. Decrease of hepcidin concentration coexisting with high level of erythropoletin in umbilical cord blood in children of smoking pregnant women may be the cause of subclinical deficiency of iron in the newborn.