The mainstreaming process has significantly altered the means of access to mental health services in Australia. Increasingly people seeking mental health care present at general hospital emergency departments. The triage system, which has proven effective for prioritizing physical illness and injury, has proven problematic when applied to mental health-related problems. This paper presents the results of a study undertaken in the emergency department of a Victorian public hospital. The Mental Health Triage Scale was introduced and used independently by triage nurses and the psychiatric nurse consultants employed in the department. Following a 3-month period, the two sets of triage scores for psychiatric presentations (n = 137) were compared. The findings suggest that triage nurses are rating clients experiencing mental health problems as in more urgent need of care than their psychiatric nursing counterparts. This suggests that the introduction of the guidelines alone is insufficient, and that education is required for more effective use of the tool.