Background: Among children diagnosed with developmental delays, difficulties in self-regulation are prominent and have been linked to school readiness problems. Objective: The current study sought to examine the impact of the Kids In Transition to School (KITS) school readiness intervention program on self-regulation, with a specific focus on response monitoring skills, among children with developmental delays. Method: Children (n = 20 in the KITS group and n = 21 in a services as usual group) were administered a flanker task during which event-related potential data were collected to examine group differences in response monitoring. Results: Findings indicated that children in the KITS group showed significant enhancement of a neural index of response monitoring post-intervention. Specifically, the KITS group showed a significant change in the magnitude of their feedback-related negativity in response to negative performance feedback from baseline to post-intervention, whereas children in the services as usual group did not. There were no significant differences between the groups for the error-related negativity or the error-related positivity on incorrect trials nor were there group differences in behavioral performance on the task at the post-intervention assessment. Conclusion: Overall, these findings provide support for the plasticity of response monitoring skills in young children and support the growing literature demonstrating improved self-regulation outcomes via intervention that enhances children's response monitoring. [This paper represents the online first version of the article to be published in "Applied Neuropsychology: Child."]