Anorexia nervosa is a serious mental illness that affects women and men of all ages. Despite the gravity of its chronic morbidity, risk of premature death, and societal burden, the evidence base for its treatment-especially in adults-is weak. Guided by the finding that family-based interventions confer benefit in the treatment of anorexia nervosa in adolescents, we developed a cognitive-behavioral couple-based intervention for adults with anorexia nervosa who are in committed relationships that engages both the patient and her/his partner in the treatment process. This article describes the theoretical rationale behind the development of Uniting Couples in the treatment of Anorexia nervosa (UCAN), practical considerations in delivering the intervention, and includes reflections from the developers on the challenges of working with couples in which one member suffers from anorexia nervosa. Finally, we discuss future applications of a couple-based approach to the treatment of adults with eating disorders.