Effective management of psychiatric emergencies has emerged as an important area in the field of mental illness. Psychiatric clinical nurse specialists (CNSs), with their advanced training in psychodynamics, pathophysiology, physical assessment, pharmacology, crisis intervention, and psychotherapy, are the ideal practitioners to respond to the treatment needs of the individual and family experiencing a psychiatric emergency. This article outlines the practice domain of the psychiatric CNS in such a setting. The psychiatric CNS brings a level of expertise to the emergency department that allows for comprehensive biopsychosocial assessment, effective crisis intervention, medication management, inclusion of family dynamics, and consideration of environmental influences in treatment and follow-up.