<p>Predation influences foraging strategies, as primates must avoid being preyed on while feeding. Some populations of capuchin monkeys are the only neotropical primates that customarily use the ground for nut-cracking. This time-consuming and focus-demanding foraging activity may increase susceptibility to predation events. However, there is currently no data on predation in tool-using <i>Sapajus</i> populations. We report a snake’s (<i>Boa constrictor</i>) predatory attack on a bearded capuchin monkey (<i>S. libidinosus</i>) in a tool-using population, as well as the other monkeys’ alarm calling and threat displays. We confirm these monkeys’ predation vulnerability and discuss how they balance foraging requirements with predation risk.</p>