The aim of this work is to verify whether there are statistically significant correlations between the concentrations of lead in blood, urine, and hair in children. The sample collected in 2007 consists of 163 children of both sexes from 11-14-year-olds, living in three municipalities of Sardinia (Italy). Inductively coupled plasma atomic mass spectrometry has been used in the determination of lead concentration in biological material. For the overall sample, there is a non-significant partial correlation among the three matrices. However, for subjects with blood lead levels ≥5 μg/dL, there is a significant positive partial correlation between the lead levels in blood and hair, but not between blood and urine or between urine and hair. The results suggest that blood is the preferred biomarker to ascertain lead exposure in human populations, whereas hair can be used as a tool screening when an area is exposed to medium or high lead pollution.