This comparative focus group study explored nurses’ experiences and perceptions regarding parental participation in infant pain management in the neonatal intensive care unit (NICU). A total of 87 nurses from 7 NICUs in Finland, Sweden, and the United States participated in focus-group interviews (n = 25). Data were analyzed using deductive and inductive thematic analysis. Nurses’ experiences and perceptions varied considerably, from nurses being in control, to nurses sharing some control with parents, to nurse-parent collaboration in infant pain management. When nurses controlled pain management, parents were absent or passive. In these cases, the nurses believed this led to better pain control for infants and protected parents from emotional distress caused by infant pain. When nurses shared control with parents, they provided information and opportunities for participation. They believed parent participation was beneficial, even if it caused nurses or parents anxiety. When nurses collaborated with parents, they negotiated the optimal pain management approach for an individual infant. The collaborative approach was most evident for the nurses in the Swedish NICUs and somewhat evident in the NICUs in Finland and the United States. Further research is needed to address some nurses’ perceptions and concerns and to facilitate greater consistency in the application of evidence-based best practices.