This study aimed to characterize the perspectives of health professionals who care for children with autism spectrum disorder (ASD) in the emergency department (ED) and to determine what strategies could optimize care. Ten physicians and twelve nurses were interviewed individually. Questions related to experiences, processes, clinical decision-making and outcomes of children with ASD recently seen in the ED. Interviews were audio recorded, transcribed, and analyzed using a qualitative framework. Participants identified factors that facilitated effective care, including communication strategies, parental involvement and teamwork. Barriers identified included child characteristics, the ED environment, and competing demands. Recommendations included additional staff training and stakeholder engagement. However, making accommodations was often described as being at odds with how the ED functioned, with implications for future service planning.