The authors examined the comorbidity of DSM-IV borderline personality disorder (BPD) with other personality disorders (PD) in a series of adult monolingual (Spanish only) Hispanic psychiatric outpatients with substance use disorders. One hundred outpatients (69 men and 31 women) were assessed with the Spanish version of the Diagnostic Interview for DSM-IV Personality Disorders. PD co-occurrence in the group of patients with BPD (N= 34) was statistically compared with that in the group without BPD (N= 66). Bonferroni-corrected chi-square analysis showed significant diagnostic comorbidity with BPD for antisocial, avoidant, and depressive PD. However, analyses conducted separately by gender showed no significant comorbidity of any PD with BPD in women and significant comorbidity with antisocial, avoidant, and depressive PD in men. These results suggest that in monolingual Hispanic psychiatric outpatients with substance use disorders, gender may play a role in the nature of BPD comorbidity. The BPD diagnosis may represent a broader range of psychopathology in Hispanic men than women.