ABSTRACT. – Mediterranean rice fields constitute temporary marshes artificially kept flooded throughout spring and summer, when natural wetlands dry up. These ecosystems can play an important role as a surrogate habitat for many organisms (e.g. invertebrates, amphibians), and as a foraging habitat for others (e.g. birds). The macro-invertebrate assemblages of three conventional rice fields, i.e. treated with pesticides and mineral fertilizers were studied in Camargue (Rhône delta, French Mediterranean coast) in 1999 and 2000, with a focus on spatio-temporal variability. A total of 70 taxa was recorded, represented by 42 families. Gastropods were dominant in numbers, representing up to 93% of macro-invertebrates in some fields. Arthropods were mainly represented by Diptera, that can form more than 54% of total numbers. Our study showed some changes in Camargue rice fields since the 60’s, such as the absence of Triops cancriformis and the abundance of an exotic Planorbidae from Asia, Giraulus chinensis. Over the cultural season, taxonomic richness rapidly increased soon after flooding and stabilized after a few months. Rice field macro-invertebrate community dynamics could be divided into three main periods, each characterized by the dominance of specific groups. Although inter-field and inter-year differences in mean density of each group were observed, the seasonal succession of species always followed the same pattern. The influence of different biotic and abiotic factors on this animal community is discussed.