A total of 299 fish belonging to ten teleost species were studied in Iranian waters at the north-eastern coast of the Persian Gulf for larval trypanorhynch cestode infection. The following trypanorhynch species were identified: Callitetrarhynchus gracilis Pintner, 1931, Pseudogilquinia thomasi (Palm, 2000), Pterobothrium lesteri Campbell and Beveridge, 1996 and Pseudolacistorhynchus shipleyi (Southwell, 1929). The most abundant parasite was C. gracilis which was isolated from seven teleost species. The highest prevalence (62.9%) and dominance (0.98) were demonstrated for P. thomasi with a maximum intensity of 22 in Indian halibut Psettodes erumei. Collections of P. lesteri and P. shipleyi from the Persian Gulf represent new locality records, thus extending the known range of distribution for both species. Four new host records are established. The recorded combination of trypanorhynch species and the established host range correspond to other regions, such as off the Brazilian coast. In terms of species distribution, the north-western part of the Indian Ocean, together with the Gulf of Bengal and the Indonesian archipelago, share the same species, resulting from connected water bodies. All trypanorhynch species were isolated from the body cavity, except for P. thomasi which was recorded from the musculature of P. erumei. Relatively high intensities of infection in P. erumei may be of public health concern in the region, necessitating the consumption of well-cooked fish products.