Ghrelin is a peripheral gastric peptide involved in the regulation of eating behavior and energy homeostasis. While changes in ghrelin plasma levels have been found in anorexia nervosa, bulimia nervosa (BN) and obesity, no study has assessed circulating ghrelin in binge eating disorder (BED). Therefore, we measured plasma levels of this peptide in women with BED as compared to women with BN, obesity and healthy controls. One hundred and eighty-two drug-free women (56 bulimics, 13 non-obese and 34 obese BED subjects, 28 obese non-binge eating women and 51 non-obese healthy women) underwent psychopathological and nutritional assessments and blood sample collection for glucose and ghrelin assays in the morning. As compared to non-obese healthy women, both non-obese and obese BED women as well as obese non-binge eating women had significantly increased values of body weight, body mass index and body fat mass. Moreover, plasma ghrelin concentrations were significantly decreased in both non-obese (P<0.01) and obese (P<0.0001) BED women as well as in obese non-binge eating women (P<0.001) but not in women with BN. No significant correlations emerged between plasma ghrelin values and the frequency of binge/vomiting in BN subjects or the frequency of bingeing in BED individuals. The reduction of plasma ghrelin in non-obese and obese binge eaters as well as in obese non-binge eaters may represent a secondary change aiming to counteract their positive energy imbalance.