Magellanic tanaidacean faunas have been mainly studied in the Magellan Strait and Beagle Channel, the latter restricted to bottoms deeper than 40m. As a result, the shallow rocky bottoms of the Magellanic fjords remain largely under-studied, and their tanaidacean diversity is poorly known. In this study, tanaidacean species sampled from shallow rocky bottoms of Chilean fjords are investigated, and morphological and taxonomic considerations included. A new species of the Tanaidae, Zeuxoides troncosoi sp. nov. is described. The genus Leptochelia is recorded for the first time in Chile, and the distribution of Pancoloides litoralis is extended northwards. Specimens collected of Pancoloides litoralis and Nototanais dimorphus present morphological differences with previous descriptions, which are at present attributed to intraspecific variation derived from geographical isolation among populations, until sufficient material can be examined to determine what constitutes interspecific and intraspecific variation.