There are three kinds of resident peritoneal cells in red sea bream, which differ from those of mammals. We investigated the peritoneal cells of 17 marine teleosts species by light and electron microscopy and divided them into four types: I) only macrophages (Mφ); II) Mφ and heterophils (He); III) Mφ, He, and large cells (L); IV) Mφ, He, L, and lymphocytes as shown : Type I: Japanese amberjack, Silver whiting, Threadsail filefish, Common Japanese conger; Type II: Japanese seaperch, Olive flounder, Dusky spinefoot, Ainame, Grass puffer; Type III: Red sea bream, Chub mackerel, Yellowfin goby, Kitefin dragonet, Multicolorfin rainbowfish; Type IV: Black porgy, Tarwhine, Bartail flathead. These groups were different from the classification of other marine teleosts. The heterophils and large cells varied extensively on cell ratio, morphology, and staining properties among fishes examined in this study. Especially, the large cells of chub mackerel had strongly basophilic cytoplasm which were saturated with electron dense granules, differing from those of red sea bream. The data indicate that the presence of several kinds of resident peritoneal cells is a physiologically common phenomenon in marine teleosts.