Microrchestia is reported from Australia for the first time and two new species are described, M. bousfieldi sp. nov. From northern New South Wales and M. watsonae sp. nov. from the northern Great Barrier Reef. The new genus Cochinorchestia is established for Microrchestia notabilis (K.H. Barnard), originally described from the Cochin area in south-eastern India.
Key words: Crustacea, Amphipoda, Talitridae, eastern Australia, south-eastern India, taxonomy, new genus, new species, Cochinorchestia, Microrchestia bousfieldi, Microrchestia watsonae