Based on National Collections records, this article presents the first report of eight freshwater fish species for Uruguay in the middle and lower Uruguay River basin, extending their current distribution: Cyanocharax alegretensis Malabarba and Weitzman, 2003; Leporinus lacustris Amaral Campos, 1945; Microglanis aff. eurystoma Malabarba and Mahler, 1998; Tatia boemia Koch and Reis, 1996; Lepthoplosternum pectorale (Boulenger, 1895); Crenicichla missioneira Lucena and Kullander, 1992; C. minuano Lucena and Kullander, 1992; Apistogramma borellii Regan, 1906. These species were previously recorded either for upper Uruguay River or Paraná River.