The mental health nurse practitioner (MHNP) role in the Emergency Department is focused on assessing and intervening to assist people in mental distress. The skills and expertise associated with this role are also compatible with the provision of short-term outpatient care. This scoping study investigated the potential for a MHNP outpatient service for patients presenting through the Emergency Department with a range of undifferentiated mental health concerns. The specific aim of this study was to explore the feasibility, structure, and potential outcome measures that may be used to evaluate a MHNP outpatient service. Data for the study were gathered via an extensive literature review and two separate focus group interviews. A series of semistructured interviews conducted with key informants were also undertaken to incorporate a range of clinical, academic, health manager, consumer, and carer perspectives. Findings from the study including prospective benefits and barriers associated with the implementation of this new service are highlighted and discussed. These findings indicate that a structured and formalized MHNP outpatient service has the potential to address a current deficit in the health-care system by providing timely, accessible, primary prevention, and early intervention mental health care that better meets the needs of the public and is consistent with the Australian National Mental Health Plan (2003-2008). A MHNP outpatient service also provides an important opportunity to explore, expand, and more clearly define the unique and valuable contribution of advanced mental health nursing practice to contemporary health care.