Background: Gender identity is a relevant issue in the approach to eating disorders. Aim: To compare psychological and behavioural characteristics and traits of gender identity among women with eating disorders and its subtypes and non eating disordered female subjects. Material and Methods: An structured clinical interview based on the DSM-IV diagnostic criteria for eating disorders, the EAT-40 (Eating Attitudes Test), the Eating Disorders Inventory (EDI) and the Bem Sex Role Inventory (IBRS) were administered to 58 compulsive-purgative anorectics (AN/BN group), 15 restrictive anorectics (AN group), 33 patients suffering from eating disorder not otherwise identified, 33 purgative bulimics and to 82 female students without eating disorders. Results: Patients with eating disorders ranked significantly higher on the EAT-40 and EDI and all its items (p <0.001). The AN/BN group ranked significantly higher on the EDI (p <0.001) and on Drive for thinness, Perfectionism and interpersonal distrust (p <0.001). The AN group ranked higher on Maturity fears (p <0.001). The BN group ranged higher on Body dissatisfaction, Ineffectiveness and Interoceptive awareness (p <0.001). Patients with eating disorders were significantly identified with Feminine category and subjects without eating disorders with Androgynous and Undifferentiated categories on the IBRS (p=0.002). The AN group showed the highest percentage on Feminine category and the lowest on Androgynous and Undifferentiated categories. All the groups rejected and approved feminine, masculine and neutral qualities. Conclusions: Femininity emerged as the main trait of gender identity in patients suffering from eating disorders, in contrast to androgyny, showed by healthy women (Rev Méd Chile 2003; 131: 748-58)