The purpose of the present study was to assess body perception in eating disorders and its meaning in therapy. A total of 44 patients, 25 bulimia nervosa and 19 anorexia nervosa, admitted at a specialized in-patient treatment center participated in the present study. Body size estimation procedures (video-distortion and image-marking techniques) and self-report questionnaires were used for the assessment. No significant differences were found in actual body size estimation between the two eating disorder groups, either before or after therapy. It emerged after therapy that the outcome was not related to body size estimation. These findings suggest that there is no evidence for a serious impairment of body perception (size estimation) in eating-disordered patients, but rather for a disturbance in the emotional aspect of body image, as expressed in negative body attitudes. Body size perception does not appear to be a predictor of treatment outcome in eating disorders.