Assemblage structure and acquisition of high-value resources will usually be affected by changes in resource availability and differential competitive abilities of assemblage members. In fragmented habitats where carrying capacity limits are exceeded due to high population densities and biomass, interspecific interactions can be expected to occur at a high frequency, potentially turning into an important cost for coexistence. We studied assemblage- and guild-level patterns of interspecific interactions in two highly diverse isolated primate assemblages in southern Amazonia. Specifically, we assessed the effects of temporal variation in fruit availability on the rates of interspecific interactions between gray woolly monkeys (Lagothrix lagotricha cana), one of the largest tree-dwelling mammals of the Amazon forests, and nine syntopic primate species. This dataset includes the rates of interactions at the guild-level and assemblage-level, as well as the rates of interactions with each individual species. Additionally, the dataset provides estimations of fruit availability at both study sites.