Objective – The study aims to construct and validate a new screening questionnaire for the identification of cases at risk for eating disorders. Setting and sample – We assessed 218 female adolescent students-recruited in a vocational school in Mestre (VE) and 88 patients consecutively referred to the Eating Disorders Unit of the University of Padova. Procedure and main outcome measures – All subjects completed the new questionnaire, the Inventory for the Screening of Eating Disorders (ISED), and the Eating Attitudes Test (EAT). Sixty-two percent of female students and all the patients underwent a structured diagnostic interview (SCID for DSM-IV) for the diagnosis of eating disorders. The reliability, validity and screening ability of the questionnaire have been assessed. Results – The reliability of the ISED, measured by Cronbach's alpha, is good (α=0.87), as is the convergent validity (correlations with EAT). In order to improve the screening ability, the questionnaire has been further divided in two subscales: one for the identification of cases at risk for anorexia nervosa (ISED-AN) and the other for cases at risk for bulimia nervosa (ISED-BN). The screening ability of the two subscales is greater than that of EAT, although the difference is not statistically significant. The ISED cutoff points have greater positive predictive values than those of EAT in the screening of both anorexia nervosa and bulimia nervosa. Conclusions – The ISED appears to-be a valid and reliable questionnaire among female adolescents. Its use might improve the identification of cases at risk for eating disorders and in particular those at risk for anorexia nervosa.Other studies are needed to confirm the validity and performance of the questionnaire among samples of different ages and socio-economic status.