Evidence from macaque monkey tracing studies suggests connectivity-based subdivisions within the precuneus, offering predictions for similar subdivisions in the human. Here we present functional connectivity analyses of this region using resting-state functional MRI data collected from both humans and macaque monkeys. Three distinct patterns of functional connectivity were demonstrated within the precuneus of both species, with each subdivision suggesting a discrete functional role: (i) the anterior precuneus, functionally connected with the superior parietal cortex, paracentral lobule, and motor cortex, suggesting a sensorimotor region; (ii) the central precuneus, functionally connected to the dorsolateral prefrontal, dorsomedial prefrontal, and multimodal lateral inferior parietal cortex, suggesting a cognitive/associative region; and (iii) the posterior precuneus, displaying functional connectivity with adjacent visual cortical regions. These functional connectivity patterns were differentiated from the more ventral networks associated with the posterior cingulate, which connected with limbic structures such as the medial temporal cortex, dorsal and ventromedial prefrontal regions, posterior lateral inferior parietal regions, and the lateral temporal cortex. Our findings are consistent with predictions from anatomical tracer studies in the monkey, and provide support that resting-state functional connectivity (RSFC) may in part reflect underlying anatomy. These subdivisions within the precuneus suggest that neuroimaging studies will benefit from treating this region as anatomically (and thus functionally) heterogeneous. Furthermore, the consistency between functional connectivity networks in monkeys and humans provides support for RSFC as a viable tool for addressing crossspecies comparisons of functional neuroanatomy.brain connectivity Í functional MRI Í posteromedial cortex Í resting state C ompared with the lateral surface of the parietal lobe, the functional organization of the medial parietal wall has been relatively neglected. Often referred to as the precuneus, this region has been implicated in high-level cognitive functions, including episodic memory, self-related processing, and aspects of consciousness (1-3). Located in the dorsal portion of the posteromedial cortex (PMC) between the somatosensory and visual cortex, superior to the posterior cingulate and retrosplenial cortex, the precuneus is well situated to play a multimodal, integrative functional role (Fig. 1, Top). Its implication in many higher cognitive functions strongly suggests the presence of functional subdivisions (2, 4), although the neuroimaging literature traditionally has treated it as a homogeneous structure and typically has failed to distinguish between the precuneus and the neighboring posterior cingulate/ retrosplenial cortex.The question of how best to subdivide the human precuneus has been a source of controversy for almost a century. The cytoarchitectonic map of Brodmann (5, 6) as it appears in the atlas of Talairach and T...