The main aim of this study is to try to see if, despite the diagenetic changes undergone by the fossil bones buried in Venta Micena (Orce, Spain), the concentration of trace elements permits the differentiation of particular groups. It is possible that some chemical elements allow us to identify different dietary groups in accord with their archaeological context. Different multivariant methods—correlation, principal component analysis and cluster analysis—were applied to the data, and in all cases the results show that two elements (Ba and Zn) seem able to discriminate between groups with different diets. In this sense, diagenesis cannot explain all the variability found in the concentrations of trace elements in fossils from the Orce region. © 1998 John Wiley & Sons, Ltd.