In Vietnam, the family Diodontidae is currently represented by six species belonging to three genera, namely Cyclichthys orbicularis Bloch, 1785
C. spilostylus (Leis & Randall, 1982)
Diodon holocanthus Linnaeus, 1758
D. hystrix Linnaeus, 1758
D. liturosus Shaw, 1804
and Lophodiodon calori (Bianconi, 1854). In this paper, the authors provide the data of species description, natural history, distribution, and identification key of afore mentioned species.