The triage of patients in the emergency department with mental health problems has long been a matter of concern for all involved in the process. The issues revolve around three key points. 1) Registered nurses who work in emergency triage are generally poorly equipped educationally to deal with clients with mental health problems; 2) the Australasian Triage Scale contains only brief descriptors of mental illness and 3) an effective interface between emergency departments and mental health services is essential for mental health patients to receive equitable care. An analysis of the literature demonstrates these issues are evident and two models of emergency mental health triage emerge quite strongly. The first is the development of triage scales tailored to mental illness that is similar to the Australasian Triage Scale. The second is the development of assessment guidelines to determine acuity.Conclusions:Emergency departments that have introduced these models of mental health triage have reported an increase in RN confidence to triage mental health patients, reduced waiting times for mental health patients and improved collaboration between emergency departments and mental health services. However, the implementation of these programs raises issues regarding consensus on the preferred model of triage and the education required for staff working in emergency departments to support these models of practice.