We describe a brush-finch (Emberizidae: Atlapetes) from central Peru, where it inhabits humid scrub on both sides of the deep canyon formed where the Rio Mantaro intersects the eastern Andean ridge. The species probably has a very restricted range. In another paper in this issue, by J. Garcia-Moreno and J. Fjeldsa, its phylogenetic relationships and taxonomic rank are discussed in a broader context, based on mtDNA data.