[Inventories of Crustacea and more generally aquatic invertebrates in the Camargue (Rhone Delta) have mainly involved Copepoda, Ostracoda, and Cladocera. Data on Decapoda have most often been collected in general faunal surveys and remain fragmentary, and this group has not been the subject of any special study. Over the period 1988-96, eleven species of Decapoda were recorded from fresh and brackish water in the eastern part of the Camargue. For two of these: Penaeus kerathurus (ForskAl, 1775) and Palaemonetes varians (Leach, 1814) this study is the first published record for the region. The temporal trends and the habitat distribution of the various species, together with factors influencing this distribution, the migrations within the Camargue hydrosystem, and the arrival of introduced species are discussed., Inventories of Crustacea and more generally aquatic invertebrates in the Camargue (Rhone Delta) have mainly involved Copepoda, Ostracoda, and Cladocera. Data on Decapoda have most often been collected in general faunal surveys and remain fragmentary, and this group has not been the subject of any special study. Over the period 1988-96, eleven species of Decapoda were recorded from fresh and brackish water in the eastern part of the Camargue. For two of these: Penaeus kerathurus (ForskAl, 1775) and Palaemonetes varians (Leach, 1814) this study is the first published record for the region. The temporal trends and the habitat distribution of the various species, together with factors influencing this distribution, the migrations within the Camargue hydrosystem, and the arrival of introduced species are discussed.]