The developing fetus probably represents one of the most vulnerable subgroups of the general population to the toxic effects of trace elements. There have been numerous reports of abortion or fetal malformation due to excessive exposure of the expectant mother to mercury and other trace elements. This investigation was aimed at gaining information on the levels of trace elements present in the blood of a term fetus, and on the relationship of these levels to the levels found in the placenta and selected maternal tissues. Once transplacental passage of the trace elements and their levels in the placenta and fetus is established, other researchers may attempt to ascertain whether these conditions actually result in overt or subtle impairments of the developing fetus. This study took advantage of the opportunity provided by normal deliveries to obtain simultaneous tissue samples from a mother and her child. Maternal-fetal sets consisting of maternal venous blood, cord blood, placenta, maternal scalp hair, and public hair were collected and analyzed for the following 16 elements: boron, barium, cadmium, chromium, copper, iron, lead, lithium, manganese, nickel, selenium, silver, tin, vanadium and zinc.