The aim of this study is assessing interactions between attachment style and personality in predicting body dissatisfaction (BD). A total of 586 outpatients with eating disorders (EDs) were recruited: 101 with anorexia nervosa, restricting type; 52 with anorexia nervosa, binge-eating/purging type; 184 with bulimia nervosa, purging type; and 249 with an eating disorder not otherwise specified. Participants completed Temperament and Character Inventory, Body Shape Questionnaire, Beck Depression Inventory, and Attachment Style Questionnaire. An insecure attachment was found in all EDs, as well as in eating disorder not otherwise specified. In all diagnostic groups, need for approval, as measured by the Attachment Style Questionnaire and depressive symptomatology, was found to be the best predictor of BD. Personality traits are weaker predictors of BD. This study supports the hypothesis that attachment insecurity is directly correlated with BD, core element in predicting and perpetuating EDs, independently of personality. Implications for treatment are discussed.