The usefulness of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the Personality Assessment Inventory (PAI) in the classification of patients diagnosed with Borderline Personality Disorder (BPD) was investigated. Twenty-two female inpatients diagnosed as having BPD and 22 female student control participants participated in the study. Those who scored 70 or above on the Borderline Features (BOR) scale of the PAI were classified as BPD. For the MMPI-2, participants with profile configurations of 8-4-2, 8-2-4, 8-4-7, or 8-2-7 were classified as BPD. Eighty-two percent of the patients and 77% of the students were classified correctly using the PAI, whereas 9% of the patients and 95% of the students were classified correctly based on the MMPI-2. The discriminant function for the selected scales of the PAI classified 86% of the participants correctly, and the discriminant function for the selected scales of the MMPI-2 classified 84% of the participants correctly. This suggests that both tests include items that discriminate between two groups. Overall, the classification of participants based on the BOR scale of the PAI was more accurate than the classification of participants using the profile configurations of the MMPI-2. Implications for the assessment of BPD are discussed. (Author)