BACKGROUND: People living with mental illness form a significant component of individuals presenting to emergency care services. Ambulance care embraces the care and treatment given to people of all ages who have suffered a sudden illness or injury and is carried out twenty-four-seven, regardless of setting and organizational belonging. AIM: The aim was to explore ambulance clinicians' competence requirements in caring for people living with mental illness. METHOD: The study had a deductive and explorative design. A Delphi method was adopted using a group of experienced individuals recruited from the emergency care chain and non-governmental organizations (N = 15). An initial open-ended questionnaire was distributed covering three questions about
(1) knowledge, (2) skills and (3) attitudes that ambulance clinicians need to care for people living with mental illness. The informants' answers were analysed using a manifest content analysis ending up in statements designed into a questionnaire that was sent out digitally in two rounds. RESULTS: The 57 statements that reached consensus could be categorised as referring to knowledge (n = 26), skills (n = 13) and attitude (n = 18). CONCLUSION: Ambulance clinicians are expected to manage a range of incidents involving people living with mental illness, demanding knowledge of mental illness and the skills of mental health assessment, to ensure ambulance clinicians have the ability and non-judgmental attitude to make appropriate decisions within a caring encounter.