BACKGROUND There are marked gender differences in the attitudes towards eating behaviors. OBJECTIVE To compare gender identity traits among females with eating disorders and subjects of both sexes without eating disorders. METHODS An structured clinical interview based on the DSM-IV diagnostic criteria for eating disorders, the Eating Attitudes Test (EAT-40), the Eating Disorders Inventory (EDI) and the Bem Sex Role Inventory (BSRI) were administered to 119 female patients that fulfilled the DSM-IV criteria for anorexia nervosa and/or bulimia nervosa and/or eating disorders not otherwise specified (FCT group), 89 males (MST group) and 63 females (FST group) without eating disorders. RESULTS The FCT group ranked significantly higher than the FST group on the EAT-40 and EDI and all its items (p < 0.001). There were no significant differences between FST and MST groups. The FST group ranked significantly higher than the MST group on the Drive for thinness (p = 0.003) and Body dissatisfaction (p = 0.009). The MST group scored significantly higher than the FST group on Perfectionism (p = 0.020) and Interpersonal distrust (p = 0.008). The FCT group was significantly identified with Feminine and Masculine categories and the FST group with Androgynous and Undifferentiated categories on the BSRI (p = 0.001). Comparatively, the MST group was significantly identified with Masculine category and the FST group with Feminine category on the IBRS (p = < 0.001). All groups rejected and approved feminine, masculine and neutral qualities. The higher correlations were observed among feminine quality on the BSRI with the total score on the EAT-40 (r = 0.46). Drive for thinness (r = 0.51) and Body dissatisfaction (r = 0.41). CONCLUSIONS Femininity emerged as the main trait of gender identity in patients with eating disorders, in contrast to androgyny showed by male and female subjects without eating disorders. Females without eating disorders were more motivated to achieve thinness and displayed more body dissatisfaction than males.