Objective Previous studies assessing the potency of cognitive remediation therapy (CRT) have largely focused on performance‐based assessments and how these change during the course of the intervention. Little is known of behavioural manifestations of such changes, and no previous studies have studied parental reports before and after CRT. Method Patient and parental self‐reports of executive function using the Behaviour Rating Inventory of Executive Function (BRIEF) were obtained for 17 adolescent patients in treatment for anorexia nervosa before and after CRT. Results Results indicated that patients scored significantly lower on the BRIEF shift subscale after CRT, whereas parental reports revealed significantly lower scores on the shift and emotional control subscales, and on the two composite indices Behavioural Regulation Index and Global Executive Composite. Case‐wise comparisons support variations in executive functions in adolescents with anorexia nervosa. Discussion Changes are evaluated in light of the relationship between patients and parents and with regard to the limitations of the study design. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.