Brain structure scaffolds intrinsic function, supporting cognition and ultimately behavioral flexibility. To evaluate the association between structure and function we assessed whether regions with similar microstructure would also be functionally connected in humans and macaques. This microstructural profile similarity approach has been previously developed in the big brain (Paquola, 2018). In humans, structure-function coupling was highest in regions of unimodal cortex and lowest in transmodal cortex. Structure-function uncoupling in non-human primates had a similar spatial distribution, but we observed an increased coupling between structure and function in association regions in macaques relative to humans.