Background <p>Anxiety due to a phobia of normal body weight is a core feature and maintenance factor of anorexia nervosa (AN). This is the first study to explore the efficacy and acceptability of using a novel imaginal exposure response prevention group to target fears associated with being a normal body weight to reduce anxiety in adolescents with AN.</p> Methods <p>The lead author adapted an I-ERP manual used to treat AN in adults in 1–1 therapy. Content was adapted for an adolescent population, sessions reduced from 10 to 4 and was delivered in a group format with audio recordings to be more accessible for patients. Nineteen patients with AN completed the group and the group therapist collected outcome measures before and after the intervention. A paired samples <i>t</i>-test was used to assess change in eating disorder psychopathology (EDEQ), anxiety and depression (RCAD) and fear of food (FOFM). Qualitative feedback to assess acceptability was also gathered.</p> Results <p>Statistically significant reduction in anxiety in a variety of situations pertaining to weight and shape was found after completion of the group. There were no significant changes shown in eating disorder psychopathology. Adolescents provided qualitative feedback which suggested the intervention was acceptable for users.</p> Conclusions <p>I-ERP which has been adapted for adolescents with AN in a group format seems to improve eating disorder psychopathology and reduce weight, shape, social and separation anxiety and phobias when used as an adjuvant to inpatient treatment. Further controlled research is advised.</p> Level of evidence <p>Level III.</p>