In a sample of 76 women participating in a clinical treatment trial for bulimia nervosa, we examined the clinical differences between subjects with and without concurrent personality disorders and the ability of “self-directedness” (a character scale of Cloninger's Temperament and Character Inventory) to predict the presence of personality disorder. Sixty-three percent of the sample had at least one personality disorder diagnosis. Fifty-one percent of personality disorders were in cluster C, 41% were in cluster B, and 33% were in cluster A. The presence of personality disorder was associated with greater depressive symptoms, worse global functioning, laxative use, greater body dissatisfaction, higher harm avoidance, and lower self-directedness. As hypothesized, low self-directedness scores were associated with a markedly increased probability of a personality disorder.