In this study, several sampling campaigns of terrestrial isopods were carried out in different oases of southern Tunisia as well as in other sites outside the oases. The results made it possible to identify: in the oases, a dozen species belonging to three families Porcellionidae, Armadillidiidae and Armadillidae and in the other sites outside the oasis, only 5 species belonging to the 2 families Porcellionidae and Agnaridae. This difference in species richness could be explained by the different climatic conditions between the two sites studied. Indeed, the majority of the species collected in the oases are characteristic of the wetlands, testifying to the important role of the oases in maintaining this specific diversity of terrestrial isopods.