This study compares the core and associated features of binge eating disorder (BED) and bulimia nervosa (BN). One hundred twenty-nine adult females who were obese with BED (n = 51) or non-obese with BED (n = 32) or who had BN (n = 46) were compared using the Eating Disorder Examination-Questionnaire (EDE-Q). The BED groups were older and had a higher body mass index (BMI). The 3 groups were similar in binge frequency, but BN subjects (by definition) purged regularly. The groups differed by dietary restraint, even after controlling for BMI and age, such that the BN group had significantly higher dietary restraint than both BED groups. Cognitively, the 3 groups were similar in the intensity of dysfunctional attitudes regarding eating, weight, and shape. The BMI and age were not associated with these dysfunctional attitudes. Our findings suggest the importance of and the need to consider cognitive--as well as behavioral--diagnostic criteria for BED.