Personality disorders are common in eating disorders and preliminary reports indicate that this type of disorders implicate a poor prognosis in anorexia and bulimia nervosa. Cluster C personality disorders, particularly avoidant and dependent personality disorder are the most frequent in anorexia nervosa. In bulimia nervosa, however, cluster B personality disorders, including borderline and histrionic personality disorders, are more frequent. Furthermore, temperament could differentiate anorectic patients from bulimic patients. Eating disorders seem to be associated with high scores in neuroticism and harm avoidance. However, while anorexia nervosa patients might have higher persistence, bulimia nervosa patients seem to have an impulsive temperament. According to the character model of Cloninger, both anorexia and bulimia present lower scores in the dimension self-directedness.