The invertebrate fauna in Northern Chilean inland waters has poorly studied due the difficult access, and there are only studies on crustacea species based in scarce expeditions. The aim of the present study is do a first community study on aquatic invertebrate communities reported in Salado River, a subsaline river in north of Chile, that is a tributary of Loa River the most long river in Chile (23ºS, Antofagasta region), based on size overlap null models. The results revealed the presence of Diptera larvae (Simulium sp., Gigantodax sp., and Ortochladinae), coleoptera larvae (Elmidae), Odonata larvae, Aranae, and amphipod Hyalella kochi. The results revealed that there is a size overlap, this means that the reported species would share their ecological niches. It is the first description of niche overlap for invertebrate Chilean rivers, and the exposed results are similar for descriptions for decapods in marine environments.