Objective: Borderline personality disorder (BPD) is a high prevalence personality disorder. Pharmacotherapy is commonly used, however, a minority of studies investigated patterns of prescription for BPD, particularly in inpatients unit. We aimed to describe the clinical features and the prescribing practice for BPD patients, and to investigate the possible advantages of a single class of medications or of combined drug treatments in terms of length of stay in hospital.Methods: This is a retrospective observational study evaluating 109 BPD inpatients from June 2011 to June 2013.Results: There was evidence of an extensive use of drugs: benzodiazepines/hypnotics (85.2%), antipsychotics (78.7%), mood stabilizers (70.4%) and antidepressants (31.5%). Polypharmacy was common (83.5%). A longer length of stay in hospital was associated with the prescription of antipsychotic and/or antidepressant medication, while a shorter hospitalization was associated with the use of a mood stabilizer.Conclusions: The rates of prescription of different classes of drugs reported in our sample and in similar naturalistic' studies highlight a heterogeneous pattern of prescriptions for BPD. Mood stabilizers showed a more favourable profile in terms in length of stay in hospital than antipsychotic and/or antidepressant. Our results reiterate the discrepancy between international recommendations and everyday clinical practice.