It is essential that all EDs plan for the potential risk of aggressive behaviour of patients or their relatives at triage. There must be a safe and non-threatening physical environment, which is as private as possible whilst not exposing staff to risk. Front line staff should have minimisation-of-aggression training and protocols and procedures for dealing with challenging behaviour. Where the safety of staff and/or other patients is under threat, staff and patient safety should take priority and an appropriate security response should take place prior to clinical assessment and treatment.