<p>Grooming in primates is often structured by dominance rank and exchanged for rank-related benefits under conditions of high feeding competition. However, evidence suggests that such patterns may weaken in environments with abundant and nonmonopolizable resources. We investigated grooming patterns among adult female <i>Sapajus nigritus cucullatus</i> living in an urban forest fragment characterized by high access to anthropogenic food sources. Using grooming interactions recorded from one group, we examined whether grooming was structured by dominance rank, rank differences, or social proximity. Grooming occurred predominantly down the hierarchy and was more frequent between females that spent more time in proximity. Grooming rates were not explained by the absolute rank of groomers or groomees, nor by rank differences between interactants. These findings suggest that, under conditions of reduced feeding competition and shallow dominance hierarchies, grooming exchanges may be weakly structured by rank and better explained by proximity-based mechanisms. Because our data derive from a single group in an urban ecological context, our conclusions are necessarily limited in scope and should be interpreted as context-dependent rather than representative of the species as a whole. Comparative studies across multiple groups and ecological conditions should assess these patterns in multiple conditions.</p>