This study examined diagnostic efficiency of Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), criteria for borderline personality disorder (BPD). One hundred thirty monolingual Hispanic adults (90 men, 40 women) at an outpatient psychiatric and substance abuse clinic were assessed with the Spanish-Language Version of the Diagnostic Interview for DSM-IV Personality Disorders (C. M. Grilo, L. M. Anez, & T. H. McGlashan, 2003). The BPD diagnosis was determined by the best-estimate method. Diagnostic efficiency indices were calculated for all BPD criteria, for the entire study group, and separately by gender. Overall, the best exclusion criterion was affective instability, whereas suicidality or self-injury was the best inclusion criterion and the best predictor overall. These findings did not differ by gender, are similar to those reported elsewhere in the literature, and have implications for the refinement of diagnostic systems.