Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Although primate predation is rarely observed, a series of primate anti-predation strategies have been described. Energetic costs of such strategies can vary from high-cost mobbing, via less costly alarm calling, to low-cost furtive concealment. Here we report the anti-predation strategies of red-nosed cuxiu, Chiropotes albinasus, based on direct observations from four study sites in southeastern Brazilian Amazonia. Over a collective period of 1255 fieldwork hours, we observed nine direct interactions between raptors (all potential predators) and red-nosed cuxius. Of these, one (11%) resulted in predation. Raptors involved were: Harpia harpyja (four events), Leucopternis sp. (two events), Spizaetus tyrannus (one event), and unidentified large raptors (two events). Predation attempts occurred in flooded-forest and terra firme rainforest, were directed at both adult and non-adult cuxius, and involved both adult and juvenile raptors. Anti-predation strategies adopted by the cuxiAs included: (1) group defence and mobbing behaviour (two occasions), (2) dropping into dense sub-canopy (seven occasions), (3) alarm calling (eight occasions), and (4) fleeing to, and hiding in, dense vegetation (eight occasions). During each encounter at least two of these behaviours were recorded. These are the first published records of predation, predation attempts, and anti-predator behaviour involving red-nosed cuxiA.582353360CNEC/WorleyParsonsELETROBRASPrimate Action Fund of Conservation InternationalCristalino Jungle LodgeMuseu Paraense Emilio Goeldi/Universidade Federal do ParaCNPQConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)