OBJECTIVE: The aim of this study was to use the Eating Attitudes Test-26 (EAT-26) as a screening instrument on a specific population with a marked prevalence of binge eating disorder (BED) and eating disorder not otherwise specified (EDNOS). The EAT-26 questionnaire was used in order to identify the high-risk subjects for referral to clinical evaluation. METHOD: EAT-26 was administered to 845 subjects who, for the first time, came to the Nutritional Medicine Service looking for a diet between January 1999 and December 2002. From this initial sample, subsequently, 250 subjects were randomly selected and administered a semistructured clinical interview for DSM-IV (SCID I, version 2.0). RESULTS: Discriminant analysis provided a cutoff value of EAT-26=11. Logistic regression analysis indicated high Dieting (D) or Bulimia (B) subscale scores as a risk factor of EDNOS or bulimia nervosa (BN) cases, respectively; on the other hand, a high Oral Control (O) subscale score represented a protecting factor for BED cases. CONCLUSION: Our study tried to assess the usefulness of EAT-26 as a screening instrument for obese patients attending a Medical Nutritional Service. Results from this study suggest that a cutoff score of 11, lower than that indicated in the literature, improves the diagnostic accuracy of the EAT-26 in a high-risk setting regarding sensibility level (68.1%) and leading to a reduction of the false negative rate (31.9%).