Among other toxic compounds, tobacco smoke contains also heavy metals, for example lead. Lead can cross the placenta barrier and have negative influences on fetus development. In the study compared urine lead concentration of pregnancy women exposed to tobacco smoke (active smokers and exposed to environmental tobacco smoke--ETS) with unexposed. There was find that mean urine lead concentrations in groups of pregnant women exposed and unexposed to tobacco smoke was no different (F2,189=0.2 p>0.8). However it was found that in urine of women exposed to tobacco smoke the concentration of lead increase with increase the concentration of cotinine (r2=0.14, t106=4.2, p<<0.0001).