Recent analyses have documented differences in dental microwear between primate species with different diets, especially between primate hard-object feeders and primate leaf-eaters. Thus far, these microwear differences have only been documented for primates with vastly different foraging strategies and geographic distributions. To see if similar differences could be documented for closely related species, dental replicas from Cebus apella, Cebus nigrivittatus, and Cebus capucinus were examined using scanning electron microscopy. Quantitative analyses reveal that (1) even for closely related species, microwear differences between facets of one species are still far less than those between homologous facets of different species; and (2) the dental microwear of Cebus apella, Cebus nigrivittatus, and Cebus capucinus are still significantly different from one another. Furthermore, the data suggest that the dietary differences between these species may center around the presence or absence of hard objects in the diet.