Children and youth with autism spectrum disorder presenting in emergency departments face potential cognitive, sensory, and behavioral challenges, and it is crucial for providers to be aware of their unique needs. However, disclosure of a child’s autism spectrum disorder can be complex for parental caregivers and is not well understood. This qualitative study utilized a grounded theory approach and analyzed data from 28 parents and 16 health care providers related to autism spectrum disorder disclosure within two Canadian pediatric emergency departments. Study results indicated that participants identified benefits and risks of disclosure. Encouraging understanding, expediting service, and preparing health care providers for working with children with autism spectrum disorder were identified as benefits of disclosure. Risks related to disclosure included potential negative attributions toward the children and parental discomfort in disclosing a diagnosis in front of the children. Parents discussed the health care encounters they experienced following disclosure and provided recommendations for improving the disclosure process in the emergency department. It is recommended that future research explore the experiences of parents who choose not to disclose their child’s autism spectrum disorder. Greater awareness of the disclosure experience and the development of resources and tools to support communication between parents and health care providers are also recommended.