Anoura is a Neotropical genus of long-tongued bats containing at least 10 species, whose taxonomy has been revised substantially in recent years. Herein, we describe a new species of Anoura from the Cordillera Oriental of the Peruvian Andes, inhabiting montane forests (Yungas) at 1900–3450 m altitude, along the Río Cosñipata valley in Manu Biosphere Reserve, Cuzco; where it is sympatric with A. peruana, A. cultrata, and A. caudifer. This new species is most similar to A. caudifer and A. aequatoris, but it is distinguished from them by a unique combination of morphological characters: pelage dark; uropatagium narrow with margins densely furred; foot claws whitish; skull with a long and narrow rostrum; zygomatic arches complete and straight (in lateral view); posterolateral margins of palate without processes; braincase smoothly rounded; first upper premolar (P2) peg-like and separated from the upper canine by a wide gap; second upper premolar (P3) without anterobasal cusp; mandible long, straight, thin and delicate with a large symphysis. Principal Component Analysis separated well the new species from A. aequatoris and A. caudifer. In MANOVA analyses, followed by Bonferroni post-hoc test, the new species differed significantly from A. aequatoris and A. caudifer in six and 11 characters, respectively. The new species and A. aequatoris have montane distributions, whereas A. caudifer occurs at lower elevations. In Peru, the new species and A. aequatoris show disjunct distributions: the former in the central and southern regions, and the latter in the north-central region of the country. This suggests a vicariant effect probably related to the deep Río Apurímac. Finally, we comment on the taxonomy of the A. caudifer complex, discuss the biogeographical implications of the discovery of the new species, and suggest the recognition of a new region of endemism for small mammals in the southern Yungas, south of the Río Apurímac to Bolivia.