Interest in assessing Personality Disorders (PDs) in association with anorexia nervosa (AN) and bulimia nervosa (BN) has been accompanied by the development of several structured interview and self-report measures. In an attempt to see how the self-report Millon Clinical Multiaxial Inventory (MCMI-II) compared with the Structured Clinical Interview for DSM-III-R (SCID-II) in the assessment of PDs, we gave both instruments to 43 inpatients with a diagnosis of AN or BN. Correlation coefficient values for both categorical and dimensional comparisons were generally less than .4. Although comparable rates of positive PDs occurred for each of the three clusters (A: 30.2% vs. 34.9%, B: 25.6% vs. 18.6%, and C: 62.8% vs. 81.4% for SCID-II vs. MCMI-II), agreement for individual diagnosis and individual subjects was poor. In conclusion, the MCMI-II did not prove to be a reliable instrument for assessing axis II PDs in patients with AN and BN when compared with the SCID-II.