Ethylmercuric chloride (EtHg), at the dose of 2.5 mg Hg/kg, was administered by gavage every other day to pregnant rats from d 6 to 20 of gestation. On the 21st day of gestation, females were sacrificed to allow the evaluation of embryotoxicity and take the material for analytical determinations. Copper, zinc, iron, and calcium were determined by AAS in liver, kidneys, brain, intestines of fetal and pregnant female rats, as well as in maternal spleen, whole blood, placenta, and fetal carcass.Ethylmercury caused a decrease of the body weight gain during gestation and diminution of relative liver weight of intoxicated females. This compound also induced fetotoxic effects, evidenced by slight diminution of the length as well as the weight of fetuses.It was found that the effect of EtHg on the levels of endogenous metals is different in females and fetuses. In pregnant females, EtHg administration resulted in a significant increase of copper levels in kidneys, liver, and spleen: and in the decrease of zinc concentration in the kidneys, but an increase in placenta and blood compared with pregnant controls. EtHg induced slight decrease of iron concentration in kidneys and intestinal wall of pregnant females. The concentrations of iron in liver and kidney and of zinc in whole blood and liver were lower in control pregnant rats than those in control non-pregnant females. In fetuses of EtHg-exposed mothers, increases in kidney zinc and liver calcium levels were found, whereas tissue copper and iron concentrations were the same as in controls.