The Pacific silverstripe halfbeak, Hyporhamphus naos is one of the most commercially important fish species in Mazatlán Bay, north-western Mexico. Irrespective of its relatively small size, it is highly appreciated in the local gastronomy. Every year between April and May adults congregate to spawn in Mazatlán Bay; however, information about their parasite fauna is lacking. This study reports on the metazoan parasite fauna of H. naos. Thirty individuals were sampled during the 2022 fishing season. Nine parasite taxa were collected, including five species of ectoparasites, that is, the monogeneans Axinoides sp. and Kuhnia sp., the copepods Ergasilus sp. and Lepeophtheirus sp., and the isopod Mothocya gilli Bruce, 1986, and four endoparasites, the nematode Philometra sp., and three metacercariae including the heterophyid Opisthometra planicollis (Rudolphi, 1819), the strigeid Cardiocephaloides medioconiger (Dubois and Pérez-Vigueras, 1949), and the cyathocotylid Mesostephanus microbursa Caballero, Grocott and Zerecero, 1953. Parasites were identified using morphology, or a combination of morphology and DNA sequences. This study includes new host records for all metazoan parasites collected, except for Philometra sp. which has been previously documented infecting the gonads of H. naos. Philometra sp. was the species with the lowest prevalence (<10%), whereas O. planicollis and C. medioconiger reached the highest prevalence values with 63.3% and 50%, respectively. We discuss the factors that potentially determine the infection parameters of the metazoan parasites in the area, and the potential zoonotic importance of the cyathocotylid M. microbursa.