This chapter explains the diagnostic features of binge eating disorder (BED) and how assess these features using evidence‐based procedures. In the DSM‐5, anorexia nervosa (AN), bulimia nervosa (BN), and BED cannot be diagnosed concurrently. As such, a diagnosis of AN or BN “trumps” a diagnosis of BED. Given the complexities of measuring binge eating, experts recommend that assessment for determining diagnosis be based on an interview rather than questionnaires. Although assessment of binge eating episodes may be more reliable and/or valid when done via interviews, self‐report measures can be useful in terms of verifying the diagnosis and examining other associated clinical features and symptom change. Findings suggest that providing diagnostic feedback empathetically can increase a patient's positive emotions. Given that there are various forms of assessments for BED, each with their own limitations, future research should continue to compare the different methods of assessments used to examine the same construct.