The concentration of erythrocyte zinc protoporphyrin (ZnPP) was studied in the group of 178 mothers at delivery and their 179 neonate infants. ZnPP was measured by front-face fluorometry. Hematological screening with examination of common laboratory markers for iron-deficiency anemia (erythrocyte and reticulocyte count, mean erythrocyte volume, hematocrit, hemoglobin concentration, and serum iron) was further performed in these subjects. Erythrocyte ZnPP values were on average higher than the arbitrary norm, which is in agreement with the decreased values of hemoglobin concentration seen in a substantial part of the group. Significant statistical correlation of ZnPP values with hemoglobin concentration, serum iron, and reticulocyte count, and a less significant one with mean erythrocyte volume was found in the subgroup of mothers having erythrocyte ZnPP higher than 40 μmol/mol heme. When evaluating the entire group, correlation of only medium significance of RBC ZnPP with mean erythrocyte volume and even ...