The Taraba Sound is situated north of the Strait of Magellan within the Chilean fjord and channel system. In this inlet, samples were collected at three beach levels (supralittoral, mesolittoral and infralittoral) along four transects perpendicular to the coastline. A total of 2, 754 specimens were collected and identified, representing seven phyla and 24 operational taxonomic units (OTUs). The dominant components across the four beaches were bivalves and crustaceans, with Choromytilus chorus and Paramoera cf. fissicauda contributing significantly to zone similarity. Beaches 2 and 4, located adjacent to river mouths, had lower salinity and consequently lower species richness, abundance, diversity and evenness, particularly in the supra- and mesolittoral zones where freshwater influence is more pronounced. Our study represents the first comprehensive characterisation of intertidal benthic invertebrate biodiversity in the region. Its findings provide valuable baseline data for future research, especially considering the anticipated increase in aquaculture concession applications and the establishment of offshore sea farming centres in the region.