The recurrent use of the emergency department (ED) is associated with personality disorder diagnoses, which suggests that the patients may be commonly encountered in this setting. Both genetic vulnerabilities and environmental factors seem to be involved in the development of personality disorders. The ED is a challenging setting for making a diagnosis of a personality disorder. The most clinically significant comorbid disorder in patients with personality disorders is alcohol use disorders. Interpersonal dysfunction is the sine qua non of character disorder diagnosis. In schizoid and schizotypal personality disorders, there may be a sense of detachment in the emotional response to the patients' needs. Borderline personality disorder is a particularly challenging condition for ED staff to assess and manage. Psychiatric crisis management involves patient engagement and mobilization of their social supports. Facilitating outpatient psychiatric referral for patients with personality disorder diagnoses is an important goal for the ED.