BACKGROUND: Emergency Medical Services (EMS) are critical for improving survival in out-of-hospital cardiac arrest (OHCA). The expertise of EMS team leaders, such as emergency nurse practitioners (ENPs), may impact patient outcomes. This study aimed to evaluate the role of ENPs and their association with outcomes in OHCA. METHODS: A retrospective analysis was conducted on OHCA cases treated by EMS from 2017 to 2020. Data included ENP presence, number of healthcare personnel, patient demographics, initial rhythm, bystander CPR, physician presence, patient access time, and scene time. Primary outcome was prehospital return of spontaneous circulation (ROSC), with secondary outcome being ROSC at the emergency department (ED). RESULTS: Among 212 OHCA cases treated by EMS, ENPs were present in 14.6 % of cases. Prehospital ROSC was 11.3 %, while ROSC at the ED was 48.1 %. ENP presence was not associated with increased prehospital ROSC (p = 0.19) but was linked to higher overall ROSC rates at the ED (p = 0.03). CONCLUSIONS: Including ENPs in EMS teams may improve short-term survival outcomes for OHCA patients, particularly at the ED. Further research is needed to explore the broader impact of ENPs in prehospital care.