Objective We aimed to examine the parent-reported factors contributing to the emergency department (ED) presentation of children and adolescents with autism spectrum disorder (autism) and/or intellectual disability (ID) with behaviours of concern (BOC).

Design Qualitative study using semistructured interviews. Data were analysed phenomenologically using inductive thematic analysis.

Setting The ED of the Royal Children’s Hospital, Melbourne, Australia, a tertiary paediatric hospital.

Participants 14 parents and/or carers of children and adolescents with autism and/or ID who presented to ED for management of BOC.

Results Three themes emerged from the data: (1) Parents and carers had difficulties navigating the healthcare system and accessing appropriate community supports prior to their child’s ED presentation; (2) Families presented to ED due to an inability to manage risk and/or contain their child’s behaviour, compounded by carer burn-out; (3) Presentation to ED was considered a last resort option for many families. The ED was generally unable to assist families in the ongoing management of their child’s BOC, leading to a potential need to re-present in future.

Conclusions This study highlights the need for families of children with autism and ID and associated BOC to have improved access to appropriately skilled community health professionals, allowing their BOC to be addressed as they emerge rather than at crisis point. The findings additionally highlight the need for changes to the delivery of acute care in the management of BOC, to minimise patient distress and maximise safe and satisfactory patient outcomes.