Body size estimation and dissatisfaction can be assessed with figure rating scales (FRS). These scales represent a continuum of silhouettes where participants have to select the figure that best fits their perceived and/or ideal body. Nevertheless, current FRS have limitations (e.g., small number of figures). We therefore developed a novel FRS—the Computer-Generated Figure Rating Scale (CGFRS)—that consists of a broad continuum of 27 computer-generated women’s bodies. It was validated among a sample of 113 women from the community and its discriminant power was examined in a sample of 20 women diagnosed with eating disorders (compared to age-matched control women). The CGFRS presented satisfactory psychometric properties (sensitivity, test–retest reliability, content, construct and convergent validities). Moreover, the scale dissociated women with eating disorders from control women: the former group overestimated their body size more and had higher body dissatisfaction.