The purposes of this study were: (1) to examine multidimensional aspects of body image of individuals with bulimia nervosa (BN) at pre-treatment, post-treatment, and at follow-up, compared to a group of participants without BN; and (2) to investigate whether measures of body image predicted outcome at post-treatment and follow-up. The clinical sample consisted of 109 females with BN who were enrolled in a 12-week cognitive-behavioral group treatment program. Participants were assessed at baseline, at the completion of treatment, and at 1- and 6-month follow-up visits. The 82 females who comprised the non-bulimic sample were assessed at comparable time intervals. At baseline, the participants with BN reported greater body dissatisfaction and overestimated body size to a significantly greater degree than the comparison group, and reported a significantly smaller ideal size relative to perceived size. Results at the end of treatment indicated significant improvement in self-reported attitudinal disturbance and size overestimation, with continued reductions at follow-up. Logistic regression analyses did not demonstrate a predictive relationship between body image measures at baseline and outcome at post-treatment or follow-up, or between post-treatment and follow-up. Implications for treatment include specifying the source of body image-related distress and enhancing treatment efforts for perceptual and attitudinal aspects of body image.