We used multiaxial structured interviews and questionnaires to evaluate the ability of self-reports on seven personality dimensions to predict independent interview diagnoses of DSM-III-R personality disorders. We studied 136 consecutive adult psychiatric inpatients, excluding those with psychosis, organic mental disorders, and severe agitation. Sixty-six patients had interview diagnoses of DSM-III-R personality disorders. Most also had mood disorders. We confirmed the hypotheses that self-reports of low selfdirectedness and cooperativeness strongly predicted the number of personality symptoms in all interview categories, whereas the other factors distinguished among subtypes as predicted. Selfdirectedness and cooperativeness also predicted the presence of any personality disorder by differentiating patients varying in risk from 11% to 94%. Patients in clusters A, B, and C were differentiated by low reward dependence, high novelty seeking, and high harm avoidance, respectively. We conclude that low self-directedness and cooperativeness are core features of all personality disorders and are validly measured by the seven-factor Temperament and Character Inventory, but not the five-factor NeuroticismExtraversion-Openness inventory. Each DSM-III-R personality disorder category is associated with a unique profile of scores in the seven-factor model, providing an efficient guide to differential diagnosis and treatment.