The authors examined a group of pregnant women employed in metallurgy and in a control group. In the serum of pregnant women working in metallurgy significantly higher concentrations (19.27 micromol/l) were recorded than in the control group (16.83 micromol/l). This corresponds to a cca 13% ratio of occupational inhalation exposure of zinc saturation of the organism. The increased zinc supply was not manifested by an increased rate of the investigated obstetric pathological conditions (hypotrophy and hypertrophy of neonates, emesis gravidarum, late gestois, spontaneous abortion). A more frequent situation is chronic zinc deficiency frequently with a marked clinical symptomatology. The urinary Zn concentration in the investigated groups does not differ practically (7.95 micromol/l in the heavy industry and 6.88 micromol/l in controls). In the umbilical serum the values in both groups are substantially higher, as compared with sera of pregnant women. This suggests some form of active Zn transport across the placenta. It is, however, not clear why this transport is more marked in the control group (21.11 micromol/l heavy industry, 23.84 micromol/l in controls).