Background: Neonatal nurse practitioners have become the frontline staff exposed to a myriad of ethical issues that arise in the day-to-day environment of the neonatal intensive care unit. However, ethics competency at the time of graduation and after years of practice has not been described. Research aim: To examine the ethics knowledge base of neonatal nurse practitioners as this knowledge relates to decision making in the neonatal intensive care unit and to determine whether this knowledge is reflected in attitudes toward ethical dilemmas in the neonatal intensive care unit. Research design: This was a prospective cohort study that examined decision making at the threshold of viability, life-sustaining therapies for sick neonates, and a ranking of the five most impactful ethical issues. Participants and research context: All 47 neonatal nurse practitioners who had an active license in the State of Mississippi were contacted via e-mail. Surveys were completed online using Survey Monkey software. Ethical considerations: The study was approved by the University of Mississippi Medical Center Institutional Review Board (IRB; #2015-0189). Findings: Of the neonatal nurse practitioners who completed the survey, 87.5% stated that their religious practices affected their ethical decision making and 76% felt that decisions regarding life-sustaining treatment for a neonate should not involve consultation with the hospital’s legal team or risk management. Only 11% indicated that the consent process involved patient understanding of possible procedures. Participating in the continuation or escalation of care for infants at the threshold of viability was the top ethical issue encountered by neonatal nurse practitioners. Discussion: Our findings reflect deficiencies in the neonatal nurse practitioner knowledge base concerning ethical decision making, informed consent/permission, and the continuation/escalation of care. Conclusion: In addition to continuing education highlighting ethics concepts, exploring the influence of religion in making decisions and knowing the most prominent dilemmas faced by neonatal nurse practitioners in the neonatal intensive care unit may lead to insights into potential solutions.