Structural MRI studies have provided insight into cerebral cortex development in humans, but little is known about the development of subcortical structures. This longitudinal study measured the shape and volume of cortical and subcortical regions in MRI scans of males and females obtained between the ages of 5 and 25 years. In both sexes, the pallidum reached its peak volume first, followed by the cortex, striatum and thalamus, although there was local heterogeneity in volume change within each subcortical structure. The authors also noted sex differences in the timing of volume change in the structures.