Background: The measure of Expressed Emotion (EE) has been extensively used for the investigation of family interaction in different clinical populations. However, very few clinical data exist which clarify the nature of the relationship between family EE and eating disorders, as well as the prognostic value of the EE variables.Objective: The purpose of this study is to determine if family EE predicts psychotherapy outcome in eating disorders.Methods:Using the Standardised Clinical Family Interview (SCFI), fifty-eight eating disorder patients (45 anorexia nervosa, 13 bulimia nervosa), were randomly assigned to one of four types of psychological treatments: Family Therapy, Individual Focal Psychoanalytic Psychotherapy, Cognitive Analytic Therapy, or Supportive Therapy. An extensive evaluation for both pre- and post-treatment phases was made of the patients and their families.Results: This study showed remarkable potential for measuring family EE in families with an eating disorder patient. The results revealed that EE is sensitive to changes in the patient. Symptomatic improvement could reduce level of negative attitudes, as well as increase in positive attitudes like warmth. It also became apparent that EE can predict the treatment outcome.Conclusion: In general, the findings revealed that EE can predict the treatment outcome. This study has demonstrated that at least two factors - a family attitude (EE), and a patient attribute (symptomatology) - interact in some manner with the treatment settings in determining outcome of treatment.