Early adversity is correlated with increased risk for negative outcomes, including psychopathology and atypical neurodevelopment. The authors aimed to test the causal impact of an early parenting intervention (the Attachment and Biobehavioral Catch-Up; ABC) on children's neural processing of parent cues and on psychosocial functioning in a longitudinal randomized clinical trial.Participants (N=68, mean age, 10.0 years [SD=0.8 years]) were 46 high-risk children whose parents were randomly assigned to receive either the ABC intervention (N=22) or a control intervention (N=24) while the children were infants, in addition to a comparison sample of low-risk children (N=22). During functional MRI scanning, children viewed pictures of their own mothers and of a stranger.Children in the ABC condition showed greater maternal cue-related activation than children in the control condition in clusters of brain regions, including the precuneus, the cingulate gyrus, and the hippocampus, regions commonly associated with social cognition. Additionally, greater activity in these regions was associated with fewer total behavior problems. There was an indirect effect of early intervention on middle childhood psychosocial functioning mediated through increased activity in brain regions in response to maternal cues.These results suggest that early parenting intervention (in this case the ABC intervention) can enhance brain regions supporting children's social cognitive development. In addition, the findings highlight these brain effects as a possible neural pathway through which ABC may prevent future behavior problems among high-risk children, yielding psychosocial benefits that endure through at least middle childhood without the need to intervene with the child directly.