Core beliefs associated with eating disorders are likely to be multidimensional, and may not be adequately captured by existing measures. The current study aimed to develop such a measure and examine its relationship to eating disorder symptoms, anxiety, depression and putative diagnoses of their related disorders. Core belief items were rated by 500 female participants aged 18-65, who also completed self-report measures of eating disorder symptomatology, depression, anxiety, and self esteem. Factor analysis revealed five subscales, with themes related to (a) self loathing, (b) unassertive/inhibited, (c) high standards for self, (d) demanding and needing help and support and (e) abandoned/deprived. Thirty two items were selected for a final scale, the Eating Disorder Core Beliefs Questionnaire (ED-CBQ). The ED-CBQ subscales showed adequate internal consistency and construct (convergent and discriminant) validity. Self loathing appeared to be particularly associated with putative eating disorder diagnosis, while abandoned/deprived was more characteristic of putative anxiety and depression diagnoses. The findings suggest that negative core self beliefs relevant to those with an eating disorder are a multidimensional construct and that self loathing as a core belief merits further research and clinical attention. (C) 2010 Elsevier Ltd. All rights reserved.