A new species of Achipteriidae, Plakoribates asiaticus sp. nov., is described from ferns and club-mosses on stones of Southern Vietnam. It is the first member of this genus recorded from Vietnam. The new species can be distinguished from all known species of Plakoribates by the combination of characters: structure of rostrum (with medial indentation and three lateral small teeth on each side), morphology of lamellae (broad, with four or five teeth), body surface (notogaster micropunctate; ventral plate striate; polygonal ornamentation between genital and anal plates present), number of notogastral pores (three pairs developed), localizations of some lyrifissures (ia located between la and lm; im located anterolaterally to h₃; ip located laterally to h₁). An identification key to the known species of Plakoribates is given.