Summary A large sample of human bones from a series of archaeological sites in the south‐eastern Iberian Peninsula was selected for δ13C and δ15N stable isotope analysis. Except for some contrast samples, the remains date from the first half of the second millennium cal BC and are ascribed to the Argar Culture, which developed during the Bronze Age in south‐eastern Iberia. Most authors have considered that this region reached a high degree of social hierarchical organization at this time, as demonstrated by the funerary record, both with regard to the grave goods and to the evidence of physical effort and diseases on the human remains. Results of the isotope analysis revealed the existence of differences among the settlements studied, as well as differences over time within every settlement and among the various individuals tested. Some variances can be assigned to social classes/status and others are linked to chronological factors. In particular, changes in δ13C can be explained by the increasing aridity of the first half of the second millennium cal BC, although other causes can be put forward too.