The anorexic voice (AV) is defined as a critical internal dialogue, which has been implicated in the development and maintenance of anorexia nervosa (AN). Systematic research to explore this further requires a valid and reliable measurement tool. This study aimed to develop and assess the validity of the Experience of an Anorexic VoicE Questionnaire (EAVE-Q). EAVE-Q items were developed and checked for face and content validity through cognitive interviews with seven individuals diagnosed with AN. Participants with a diagnosis of AN (N = 148) completed the EAVE-Q, sociodemographic questions and measures of mood and quality of life to assess internal consistency and construct validity. Forty-nine participants completed the EAVE-Q twice more to assess test-retest reliability. The EAVE-Q had good face and content validity and good acceptability. Principal axis factoring resulted in an 18-item scale organized into five domains with high internal consistency (α = 0.70 to α = 0.85). Domains correlated significantly with eating disorder symptoms, psychological distress, and quality of life. The EAVE-Q did not discriminate between participants on the basis of body mass index. Test-retest reliability was moderate. Although the factor structure of the EAVE-Q requires replication in other AN samples, the EAVE-Q is the first measure of a critical internal dialogue in AN. It is hoped that it will aid future research to increase understanding of AN and the continued development of person-centred treatments.