Abstract Background Bronchiolitis is the most common reason for hospitalization in infants and is cumulatively costly for the healthcare system. Trial evidence and national guidelines support the routine use of intermittent pulse oximetry in stabilized (no oxygen supplementation) infants with bronchiolitis. However, continuous pulse oximetry use is common. Objectives To understand the barriers and facilitators important to de-implementing continuous pulse oximetry and implementing intermittent pulse oximetry in stabilized infants hospitalized with bronchiolitis. Design/Methods From December 2018 to January 2020, participants were recruited from six Ontario hospitals (3 community and 3 paediatric hospitals) in a multi-centre qualitative study. Focus groups were conducted with staff paediatricians, paediatric residents, nurses, and respiratory therapists. Interviews were conducted with caregivers of infants recently hospitalized with bronchiolitis. Participants' beliefs, attitudes, and experiences related to pulse oximetry use in bronchiolitis management were explored. Recordings were transcribed and analyzed using thematic analysis via NVivo software to understand barriers and facilitators to practice change. These were then mapped to the domains and the constructs of the Consolidated Framework for Implementation Research (CFIR). Results 67 individuals from six hospitals participated. Themes relevant to understanding barriers and facilitators to de-implementing continuous and implementing intermittent monitoring were identified. Healthcare professionals emphasized the importance of identifying and understanding who is responsible for bedside monitoring practice (physician vs. nurses). Clinical experience, knowledge of guidelines (international and local practice), importance relative to competing priorities, and the tensions amongst team members due to practice variation all influenced monitoring practice. Nurses held beliefs around the advantages of intermittent monitoring (e.g., reduced alarm fatigue, facilitation of timely discharges and reduced workload). Clinicians identified ways to clarify indications for ongoing continuous monitoring (e.g., based on clinical risk factors such as medical complexity, prematurity, and age), vs. indications to transition to intermittent monitoring (e.g., established oral feeding, sleeping without desaturations, and off supplemental oxygen). Caregivers did not express a clear preference for monitoring type, but described the stress of having a child admitted to hospital with an emphasis on the need for clear communication around the interpretation of monitors, management decisions, and care transitions. Conclusion In this multi-centre qualitative study of clinicians and caregivers, we identified barriers and facilitators that are important to de-implementing continuous monitoring and implementing intermittent monitoring. Understanding professional roles, clarity around local practice standards and supporting families' understanding of pulse oximetry monitoring practices are essential for practice change.