The Dandenong Amphipod, Austrogammarus australis (Crustacea: Paramelitidae), has gained attention by being one of the two freshwater invertebrates listed as ‘presumed extinct’ only to be rediscovered a few years later close to its type locality within the Dandenong Ranges. Subsequent surveys located new sites for this and another species, Sherbrook Amphipod, A. haasei. But the knowledge of distribution of other three Austrogammarus species remained poor due to the vague description of their type localities, complex morphology and descriptions based on only a few specimens. DNA barcoding combined with morphological analysis of specimens collected in Victoria offered an opportunity to shed new light on the taxonomy and distribution of species within this genus. The preliminary study found that five different Austrogammarus species occur within and one outside the Dandenong Ranges area. At least some of these do not match previous described species pointing to the possibility of the discovery of new species. A. haasei occurs within much wider than previously thought area while three genetically distinct populations can be recognised for A. australis. We also found that while five species occur at close proximity to each other within the Dandenongs, the populations of the sixth species occur as far as 150km apart and in different catchments. DNA barcoding provided new knowledge of the distribution of previously known and potential discovery of new species for more effective conservation and biodiversity management of this vulnerable genus.