The current study examined the relationship between ethnicity and DSM-IV personality disorders. The distribution of four personality disorders--borderline (BPD), schizotypal (STPD), avoidant (AVPD), and obsessive-compulsive (OCPD)--along with their criteria sets, were compared across three ethnic groups (Caucasians, African Americans, and Hispanics) using both a clinician-administered diagnostic interview and a self-report instrument. Participants were 554 patients drawn from the Collaborative Longitudinal Personality Disorders Study (CLPS) who comprised these three ethnic groups and met personality disorder criteria based on reliably administered semistructured interviews. Chi-square analyses revealed disproportionately higher rates of BPD in Hispanic than in Caucasian and African American participants and higher rates of STPD among African Americans when compared to Caucasians. Self-report data reflected similar patterns. The findings suggest that in treatment-seeking samples, Caucasians, Hispanics, and African Americans may present with different patterns of personality pathology. The factors contributing to these differences warrant further investigation.