Maltreated youths in foster care often experience negative developmental and psychological outcomes, which have been linked with poor response inhibition. Recent evidence suggests that childhood maltreatment is also associated with alterations in the neural circuitry underlying response inhibition. However, a burgeoning line of research has begun to explore the mitigating effects of preventive interventions on neural functioning. The current study used event-related functional magnetic resonance imaging to explore the impact of early childhood maltreatment and a preventive intervention on response inhibition in early adolescence. Thirty-six demographically similar adolescents (ages 9–14 years) completed a Go/NoGo task. The sample included nonmaltreated adolescents ( n = 14) and maltreated adolescents who were in foster care as preschoolers and randomly assigned to receive services as usual ( n = 11) or a preventive intervention, Multidimensional Treatment Foster Care for Preschoolers ( n = 11). The groups demonstrated similar behavioral performance but significantly different neural patterns. The maltreated adolescents who received services as usual demonstrated subcortical hypoactivity during successful response inhibition and subcortical hyperactivity during unsuccessful response inhibition. In contrast, the nonmaltreated adolescents and maltreated adolescents who received the intervention exhibited strikingly similar neural patterns during successful response inhibition, but the maltreated adolescents who received the intervention demonstrated prefrontal hypoactivity during unsuccessful response inhibition. These findings offer preliminary evidence that early childhood maltreatment alters the neural patterns underlying response inhibition in early adolescence and that participating in a preventive intervention could mitigate maltreatment-related effects on these neural systems.