Two new Neogene South American croakers of the genus Plagioscion (Perciformes, Sciaenidae) from marine sediments, Plagioscion marinus and Plagioscion urumacoensis, are described. These are otoliths from the lower Miocene Castillo, Cantaure and upper Miocene Urumaco Formations of the Neogene Venezuelan basin, respectively. An additional undetermined fossil species of Plagioscion was also collected from the upper Miocene to lower Pliocene Cubagua Formation. Using the function total fish length = 13.7187 + 50.8399 * Ln otolith size, the total length of P. marinus n. sp. is inferred to be from 6.05 to 38.1 cm, and for the specimens of P. urumacoensis n. sp. it is 63.3 cm. The length distribution of the fossil species overlaps the length distribution of the living freshwater species.