Introduction <p><i>Hexostoma auxisi</i> Palombi, 1943 was originally described by Palombi (1943) from <i>Auxis thazard</i> off Italy, Mediterranean Sea. The original description of this species lacks morphological and morpho-metrical data. In addition, no published sequence of this species is available in molecular engines.</p> Materials and Methods <p>Specimens of <i>Hexostoma auxisi</i> were collected from the gills of <i>Auxis rochei</i> (Risso, 1810) off the Algerian coast, Western Mediterranean. Monogenean were stained with acetic carmine, measured and drawn. Furthermore, molecular study was conducted using partial fragment of the mitochondrial cytochrome c oxidase subunit 1 (<i>cox1</i>) of parasites and a tissue sample of the fish’s gills on which the monogeneans were found.</p> Results <p>In this study, we provide morpho-anatomical and morpho-metrical data of <i>Hexostoma auxisi</i>. Our specimens are morphologically close to those described by Palombi (1943) off Italy, Mediterranean Sea. The morphological study was supported by a molecular analysis of <i>cox1</i> gene that reveals that our sequence of <i>H. auxisi</i> is distinct from its congener <i>H. thynni</i> by 20.51%.</p> Conlusion <p>The present study allowed us to confirm the taxonomic status of <i>Hexostoma auxisi</i> which belongs to the genus <i>Hexostoma</i> and the family Hexostomatidae.</p>