Reference values for Al, Cd, Co, Cu, Li, Mn, Mo, Ni, Rb, Se and Zn, and indicative intervals for Sb are proposed in serum from cord blood of 143 term newborns of the urban area of Rome. On the basis of the eligibility criteria adopted, only babies with gestational age > 37 weeks and body weight at the delivery > 2500 g, i.e., "normal" term infants, were included in this study. With the exception of Cd, Li, Ni and Sb, experimental data for each of the other analytes were found to approach a normal distribution. The estimated references values (in ng/ml) were the following: Al, 1. 12-6.79; Cd, 0.10-0.52; Co, 0.20-0.43; Cu, 140-691; Li, 0.31-2.23; Mn, 0.79-3.26; Mo, 0.36-1.56; Ni, 0.20-3.15; Rb, 196-1302; Sb, 0. 10-1.48 (indicative range); Se, 20.2-69.7; and Zn, 318-1405. For several elements, the information available in the relevant literature does not allow adequate comparisons to be performed. This was actually possible only for Cu, Se and Zn. The correlations between the weights at birth (BW), gestational ages (GA) and elemental concentrations were elucidated. As expected, significant positive correlations were found for Cu and Se with GA and BW, respectively. Strong mutual associations were observed for several other elements, but their interpretation is still debatable.