The blonde capuchin monkey (Sapajus flavius) was, until a few years ago, an endemic primate of the Atlantic Forest. Today, populations inhabit the Caatinga dry forest and these have been documented using stone tools to access encased foods. It is important to know the distribution of these sites and the characteristics of the stone tools to inform conservation actions for this primate in the Caatinga. To this end, we identified and characterized stone tool sites used by a group of blonde capuchin monkeys in the Caatinga dry forest of northeastern Brazil. For 8 months, we walked two pre-existing trails to georeference the stone tool use sites, to measure the dimensions and weight of the anvils and hammerstones, and to identify the food items processed at the sites. A total of 215 anvils and 247 hammerstones were mapped. The anvils were significantly longer than the hammerstones, while there was no difference in width. Most food remains found on the anvils were old (n = 101; 91%). Cnidoscolus quercifolius (n = 85; 77.3%) and Prunus dulcis (n = 25; 22.7%) were most common among the plant species found on the anvils. The width, thickness, and weight of hammerstones used to crack fruits of P. dulcis were significantly greater than those used to crack C. quercifolius. These results should be used as a baseline for the development of conservation actions for the species and habitat.