The X-ray microprobe at beamline X-26 of the National Synchrotron Light Source (Brookhaven National Laboratory) has been used to determine minor and trace elements in small fragments of dental calculus. This material was removed from 11 individuals found in the Norman necropolis discovered recently under the church of San Lorenzo di Aversa (Caserta, southern Italy, ca. AD 900–1200). The aim of these experiments is to develop new methods for non-destructive analysis of organic archaeological materials in studies of palaeonutrition and palaeopathology. These preliminary analyses show little variability in the main trace elements of dietary significance, such as Sr and Zn.