Despite being one of the better-surveyed regions in Brazil, the upper Rio Paran & aacute; basin still reveals relatively numerous large new species of fish. Here, we present a new uniquely colored species of the highly diverse, armored catfish genus Hypostomus. . The new species was mostly found in the Rio Grande basin, plus a single record in the main channel of the Rio Paran & aacute;. Hypostomus caudofasciatus n. sp. is remarkable by its large eyes, and it completely differs from congeners by having four longitudinal dark stripes on the flanks and a caudal fin with conspicuous longitudinal dark stripes on a yellow background (unique in Hypostomus). ).