The comorbidity between substance-use disorders and borderline personality disorder (SUD-BPD) with other psychiatric disorders has been little studied. A total of 937 drug-dependent patients were evaluated using semistructured interviews and 13.7% were SUD-BPD patients. After multivariate analysis, gender, Affective Disorder (OR 2.59), Anxiety Disorder (OR 1.90), Eating Disorders (OR 4.29), Cocaine (OR 2.16), benzodiazepine dependence (OR 1.90), early age of onset of drug consumption (OR 0.94), and dependent (OR 4.04), paranoid (OR 3.70) and antisocial personality disorders (OR 3.46) were associated with SUD-BPD. Several psychiatric comorbidities are the norm in SUD-BPD patients; therefore these patients are a challenge for clinicians.