AimsTo investigate registered nurses' (RNs') and physicians’ knowledge, attitudes, and experiences regarding assessing and managing pain in infants at seven level III neonatal intensive care units (NICUs) in Sweden. DesignDescriptive and explorative study using an online questionnaire. MethodsA researcher-developed online questionnaire with 34 items about knowledge, attitudes, and experiences regarding pain assessment and management was emailed to 306 RNs and 79 physicians working at seven neonatal intensive care units (NICUs) in Sweden. ResultsMost NICUs had pain assessment guidelines, but there was a discrepancy regarding interprofessional discussions of pain assessments. A total of seven different pain assessment instruments were reported from the included NICUs and RNs were reportedly those who usually performed the pain assessments. Most respondents expressed a positive attitude toward pain assessment but recognized a lack of intervention after the assessment. Forty-six percent (n = 11) of the physicians said they had sufficient knowledge of assessing pain using pain assessment instruments, versus 75% (n = 110) of the RNs. Difficulties assessing pain in certain populations of infants, such as the most premature infants and infants receiving sedative medicines, were recognized. ConclusionsRNs in this study reported that their pain assessments did not lead to appropriate pain management interventions. They were thus discouraged from further pain assessments or advocating for ethical pain management. An interprofessional team effort is needed to effectively assess and manage pain in neonates.