Reviewedthe distribution and movementsof southern right whale dolphins (Lissodelphisperonii) off western South America. Data consist of 36 confirmed records from 1823through 1990,almost half unpublished and including records of specimenstaken incidentally in net fisheries, strandings and sightingswhich could be authenticated.Preliminary surveyssuggestthat L. peronii may be one of the most common cetaceansoff northern Chile, where recently gill net entanglementshave become alarmingly common. Mean group size was 368. Assessmentof population density and fishery mortality is urgently needed.The normal habitat of right whale dolphins off South America appears strictly pelagic. Two specimenscaught near Pucusana(12° 30′ S), the second and third confirmed records for Peru, extend the known range north five degrees.North of 25 oS,more records were registeredin July-September than in all other months combined, suggestinga northbound migration in australwinter andspring.Off Chile, between25°and40°S,right whaledolphinswereseenyear- round. Distribution extendsto at least 170km offshore north of 40°Sand 250km off the southern Chilean coast; south of Cape Horn it is circumpolar in the West Wind Drift.