Adult anorexia nervosa (AN) often is persistent, significantly erodes quality of life for both the patient and loved ones, and carries high medical and psychiatric comorbidity. Whereas individual psychotherapy for adult AN leads to improvement in some patients, recent findings indicate that the magnitude of improvement is limited: Only a small percentage of individuals fully recover and dropout rates are high. Thus, it is important to build upon current interventions to improve treatment response. We present results from an open trial of a couple-based intervention for adult anorexia nervosa as an adjunct treatment to standard multidisciplinary care. Twenty couples received treatment over approximately 26 weeks, including a couple-based intervention, individual CBT sessions, psychiatry visits for medication management, and nutritional counseling sessions. The results indicate that patients improved at posttest and 3-month follow-up on a variety of AN-related measures, anxiety and depression, and relationship adjustment. Partners also improved on anxiety, depression, and relationship adjustment. In an exploratory analysis, the multicomponent couple treatment intervention was benchmarked to well-conducted randomized controlled trials of individual therapy for AN; the couple intervention seems to compare favorably on AN-related measures and was associated with a lower dropout rate. In spite of methodological limitations, the findings suggest that including partners in the treatment of adult AN holds potential for bolstering treatment outcomes.