We revise the diagnosis of the Gotocotylidae Yamaguti, and accept Gotocotyla Ishii and Cathucotyle Lebedev as valid genera. We synonymise Pseudomicrocotyle Sandarsand Swakopella Lebedev & Parukhin with Gotocotyla . The number of nominal species in the familyis reduced from ten to four, and six new species are described from newmaterial. Members of Gotocoty lahave asymmetrical clampswith a single row of internal ribs, and those of Cathucotyle have more or less symmetrical clamps withtwo rows of ribs. Members of both genera can be distinguished from congenersby the morphology of clamp sclerites and/or spines of the male copulatoryorgan, and the number of vaginae (0–2). The following species arerecognised: Gotocotyla acanthura (Parona & Perugia), G.africanensis , sp. nov., G.bivaginalis (Ramalingam), G.elegatis (Meserve), G.heapae ,sp. nov., G.niphonii , sp. nov., G.queenslandici , sp. nov., Cathucotyle cathuaui Lebedev, C.filipinensis , sp. nov.and C.sinensis , sp.nov. Gotocotyla acanthura as recognised here may be aspecies complex, but we could not distinguish the morphologies of individualsfrom different hosts and localities. There is strong evidence that larvae andyoung juveniles of G.acanthura infect intermediate hostsfor short periods (mostly pelagic fishes, belonging to at least eight orders),until eaten by the final host.