Purpose: The purpose of this study was to identify factors influencing neonatal pain management by nurses in order to provide evidence-based data for the development of more efficient neonatal pain care programs. Methods: This study used a descriptive research design to survey 204 registered nurses working in neonatal intensive care units and nurseries in Busan. Data collection was done from July to September 2010. General knowledge of pain and pain scale, pain intervention, neonatal pain management, and barriers to pain management were measured. Data were analyzed using stepwise multiple regression with SPSS 17.0. Results: it was found that among the factors affecting neonatal pain management by nurses, the unit where the nurse worked was the most important influential factor, followed by knowledge of pain management, education level, and barriers from medical personnel in that order. The explanatory power of these four variables accounted for 42.0% of neonatal pain management. Conclusion: Study results indicate that it is necessary to develop education programs to increase knowledge of neonatal pain management for nurses caring for neonates. Also, plans for reduction of obstacle factors in medical personnel should be prepared.