In recent years, more andmore emphasis has been placed on the investigation of sex differences in the human
brain. Noninvasive neuroimaging techniques represent an essential tool in the effort to better understand the
effects of sex on both brain structure and function. In this review, we provide a comprehensive summary of
the findings that were collected in human neuroimaging studies in vivo thus far: we explore sexual
dimorphismin the human brain at the level of (1) brain structure, in both gray andwhitematter, observed by
voxel-based morphometry (VBM) and diffusion tensor imaging (DTI), respectively; (2) baseline neural
activity, studied using resting-state functional magnetic resonance imaging (rs-fMRI) and positron emission
tomography (PET); (3) neurochemistry, visualized by means of neuroreceptor ligand PET; and (4) taskrelated
neural activation, investigated using fMRI. Functional MRI findings from the literature are
complemented by our own meta-analysis of fMRI studies on sex-specific differences in human emotional
processing. Specifically, we used activation likelihood estimation (ALE) to provide a quantitative approach to
mapping the consistency of neural networks involved in emotional processing across studies. The presented
evidence for sex-specific differences in neural structure and function highlights the importance of modeling
sex as a contributing factor in the analysis of brain-related data.