Abstract The neural bases of emotion are commonly measured using blood-oxygen-level-dependent (BOLD) signal and the late positive potential (LPP) event-related potential (ERP) component, but rarely together in the same individuals. Despite evidence of developmental changes in processing socio-emotional signals (e.g., faces) as reflected by both BOLD and LPP indices of brain maturation, the literature on the correspondence between these measures is limited to healthy adults, leaving questions regarding such correspondence across development and in clinical populations unaddressed. We examined the relationship between BOLD and LPP during an emotional face processing task in a large sample of youth (N?=?70; age 7ñ19 years) with and without anxiety disorders, and tested whether BOLD signal in regions corresponding to LPP may account for age-related decreases in LPP. Greater activation in bilateral inferior frontal gyrus (IFG)/orbitofrontal gyrus (OFG), left supplementary motor area, right superior parietal lobule, and bilateral amygdala correlated with enhanced LPP to emotional faces in both anxious and healthy youth. Older youth exhibited reduced activation in bilateral IFG/OFG and bilateral amygdala, as well as reduced LPP. Decreased right IFG/OFG activation mediated the association between age and LPP. These findings support correspondence between these measures and need for multi-method approaches and indicate that age-related decreases in LPP may be driven, in part, by decreased IFG/OFG activation.