Psychologists consider emotion regulation a critical developmental acquisition. Yet, there has been very little research on the neural underpinnings of emotion regulation across childhood and adolescence. We selected two ERP components associated with inhibitory control—the frontal N2 and frontal P3. We recorded these components before, during, and after a negative emotion induction, and compared their amplitude, latency, and source localization over age. Fifty-eight children 5–16 years of age engaged in a simple go/no-go procedure in which points for successful performance earned a valued prize. The temporary loss of all points triggered negative emotions, as confirmed by self-report scales. Both the frontal N2 and frontal P3 decreased in amplitude and latency with age, consistent with the hypothesis of increasing cortical efficiency. Amplitudes were also greater following the emotion induction, only for adolescents for the N2 but across the age span for the frontal P3, suggesting different but overlapping profiles of emotion-related control mechanisms. No-go N2 amplitudes were greater than go N2 amplitudes following the emotion induction at all ages, suggesting a consistent effect of negative emotion on mechanisms of response inhibition. No-go P3 amplitudes were also greater than go P3 amplitudes and they decreased with age, whereas go P3 amplitudes remained low. Finally, source modeling indicated a developmental decline in central-posterior midline activity paralleled by increasing activity in frontal midline regions suggestive of the anterior cingulate cortex. Negative emotion induction corresponded with an additional right ventral prefrontal or temporal generator beginning in middle childhood.