Reproductive mode of the two widespread speciesPolyprion americanus(Bloch and Schneider, 1801) andP. oxygeneios(Schneider in Bloch and Schneider, 1801) was investigated in specimens from New Zealand waters. Analysis of sex ratios, length frequencies and gonad morphology indicates that both species are primary gonochorists. Published suggestions thatPolyprionspecies are hermaphroditic and undergo sex change are rejected.