A collection of crabs assembled during the KUW 2009 expedition to Mayotte Island and deposited in the Muséum national d’Histoire naturelle Paris is studied. In total 202 species are recognized, 138 of them being new records for the Island and a list of brachyuran crabs is documented and illustrated with photographs. A complementary list of all crabs previously in taxonomic literature from Mayotte and its nearest Islands (Comoros Islands, Glorieuses Islands and marine banks of Zélée, Geyser and Leven) is also provided. In total 298 crabs are identified from the region, the richness of this fauna is discussed with zoogeographic considerations and the prospects for further studies are outlined.