The error-related negativity (ERN) is a negative deflection in the event-related potential occurring when individuals make mistakes. The ERN has been proposed as a biomarker for anxiety and a substantial amount of research suggests the ERN increases across development. Further, the ERN may relate to individual differences and the development of cognitive control. Despite the large quantity of research on this topic, there have been no studies focusing on the relationship between pubertal hormones and the ERN. Previous work suggests developmental increases may begin sooner for girls than for boys, suggesting that puberty may impact the ERN. The current study examined the relationship between pubertal hormones and the ERN amplitude in a sample of 99 females between 8 and 14 years old. Each participant and the parent who accompanied them completed the Pubertal Developmental Scale (PDS) to assess the degree to which pubertal indicators are present. Participants also completed a Go/NoGo Task while EEG was recorded and participants provided saliva samples for hormone assays. Results indicated that ERN was significantly related to both the dehydroepiandrosterone (DHEA) hormone and PDS scores. A simultaneous multivariate regression suggested that DHEA levels significantly predict the ERN, even when controlling for age, behavioral variables, and PDS. These findings suggest that ERN amplitude is related to DHEA levels, further linking puberty to developmental increases in the ERN. Future research should examine this relationship in the context of developmental increases in anxiety symptoms.