the simuliidae is a family of diptera with approximately 2072 described species worldwide. the females of the majority of the species feed from vertebrates' blood, which makes them a significant plague that affects both men as well as cattle, birds, and other vertebrates. the objective of this paper is to create an inventory of simuliidae and to reveal certain aspects of the biology and distribution of this family of aquatic insects in the nahuel huapi national park. moreover, information on the zoogeography of simuliidae in patagonia is provided. five genera, 3 subgenera and 32 species simuliidae are recorded from patagonia: cnesia (three spp.), cnesiamima (one sp.), gigantodax (14 spp.), paraustrosimulium (one sp.), simulium (ectemnaspis) (one sp.), s. (psaroniocompsa) (one sp.) and s. ( pternaspatha) (11 spp.), at present, we have collected all five genera, one subgenus of simulium (pternaspatha), and 19 species of simuliidae in the park, which amounts to 57% of the simuliidae fauna in this area. puerto blest, a characteristic area of the high-andean phytogeographical province (humid forest), showed the highest diversity of simuliidae.