Children raised in institutions display deficits in error monitoring and increased psychopathology. Deficits in error monitoring might be a pathway for the emergence of psychopathology in previously institutionalized adolescents. Here we investigate the impact of early psychosocial deprivation and a foster care intervention on error monitoring and its association with internalizing and externalizing behavioral problems in adolescence A modified Flanker task assessed error monitoring in 16-year-old adolescents from the BEIP. The ERN and mid-frontal theta power were computed as indices of neural responses of error monitoring. Adolescents who experienced early institutional rearing and were subsequently placed into foster care showed comparable behavioral (RT, accuracy) and neural (ERN, theta power) measures of error monitoring to their never institutionalized peers; whereas adolescents who received care as usual showed both perturbed behavioral performance and neural responses. Longer duration of institutional care was associated with a reduction in mid-frontal theta power. The results further demonstrated a link between error monitoring as measured by ERN and mid-frontal theta and externalizing-ADHD behavioral problems in adolescents who continued receiving care as usual. The results highlight the long-term positive impact of early foster care placement and perturbations due to prolonged institutional care in neural responses of error monitoring.Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.