The life cycle of tetraphyllid cestodes is complex, involving plerocercoid larvae that can utilize teleost fish as a second intermediate host or paratenic host, in which they can exhibit a diversity of plerocercoid larvae. The objective of this study is the morphological characterization of tetraphyllid plerocercoids in Trichiurus lepturus Linnaeus, 1758 from the coast of the state of Rio de Janeiro, Brazil. In July 2018, 33 specimens of T. lepturus were obtained from professional fishermen, captured near the Cagarras archipelago (23°1'52"S, 43°11'56"W), state of Rio de Janeiro, Brazil. The hosts were weighed, measured, and subjected to necropsies under a stereoscopic microscope for the collection of plerocercoids. The collected specimens were fixed and prepared following traditional helminthological techniques. Morphological and morphometric studies of the parasites were conducted, co...