In this paper, nine species of Monogenea were recorded parasitizing the gills of Hoplias aff. malabaricus from the Upper Paraná River. The host were collected by gillnets in different regions to the Upper Paraná River Floodplain between March 2010 and March 2011. The parasites were quantified, fixed and preserved according with specialized literature. All hosts analyzed were parasitized by monogeneans. The monogeneans species were recorded Urocleidoides malabaricusi, U. cuiabai, U. eremitus, U. brasiliensis, Cosmetocleithrum bulbocirrus, Vancleaveus janauacaensis, Anacanthorus sp., Dactylogyridae gen. sp. and Dactylogyridae gen. 1. sp.