Only a small proportion of the treatment of mental illness occurs in an institution or hospital. By far the most significant treatment happens in the community and in the patient’s own social and family environment. However, de-institutionalisation of mental health services has brought increasing numbers of patients to the emergency department in need of psychiatric assistance. The traditional service model of emergency departments, focusing on physical illness and injury, is being challenged. The literature review identified numerous psychiatric service models in place but dramatically highlighted the lack of a specific service model addressing psychiatric patients who present on multiple occasions [multi-presenters] in emergency departments. At present, accurate data on the effects of multi-presentation of psychiatric disorders are not available. Recent international and local research into models of service delivery management and best practice is examined.