We revised the zoogeographical distribution of mysids in the south-west Atlantic, from northern Brazil to Argentina (0° to 40°S), providing body length, and temperature and salinity range of occurrence for each species. All information concerning mysids from the south-west Atlantic was obtained from published/unpublished studies. Of currently 1128 mysids species described worldwide, only 31 were recorded in the south-west Atlantic which are distributed in 14 genera, 6 subfamilies and one family. This extremely low number of recorded species highlights the need for further studies focusing on mysids in the south-west Atlantic.
