The lateral prefrontal cortex (LPFC) plays a major role in both working memory (WM) and response inhibition (RI), which are fundamental for various cognitive abilities. We explored the relationship between these LPFC functions during childhood development by examining the performance of two groups of children in visuospatial and auditory WM tasks and a go/no-go RI task. In the younger children (59 5- and 6-year-olds), performance on the visuospatial WM task correlated significantly with that in the auditory WM task. Furthermore, accuracy in these tasks correlated significantly with performance on the RI task, particularly in the no-go trials. In contrast, there were no significant correlations among those tasks in older children (92 8- and 9-year-olds). These results suggest that functional neural systems for visuospatial WM, auditory WM, and RI, especially those in the LPFC, become fractionated during childhood, thereby enabling more efficient processing of these critical cognitive functions.