Objectives: Borderline personality disorder (BPD) is a life-threatening mental disorder. Guideline recommendations for pharmacological treatment of patients with BPD vary widely. The objective of the present study was to investigate pharmacotherapy of BPD patients in a routine clinical care setting. Methods: Data on the pharmacological treatment of 110 patients (90% female) with BPD (F- 60.3), treated in an inpatient psychiatric-psychosomatic clinic in Austria were assessed. Results: Results show that clinicians frequently prescribe psychotropic medications to patients with BPD, in many cases multiple medications. The most commonly prescribed substance groups were antipsychotics, mood stabilisers and antidepressants. The most commonly prescribed individual drugs were Quetiapine, Lamotrigine and Setraline. There was no significant difference in the different types or overall number of medications prescribed to BPD patients with vs. without comorbid diagnoses. Pharmacotherapy was not related to comorbidity. Conclusions: The present study shows that in routine clinical care settings psychotropic medications are frequently prescribed to patients with BPD, very often resulting in polypharmacy. A positive association between the number of medications and the effectiveness of the inpatient treatment program, as well as the absence of a relationship between number of medications and comorbidity contradicts the often suggested iatrogenic effect of polypharmacy. Key points Guidelines for pharmacotherapy of borderline personality disorders lack consensus Yet, clinicians frequently prescribe psychotropic medications to BPD patients Types/number of medications prescribed to patients with vs. without comorbidities are similar Larger treatment effects are observed for patients with greater numbers of medications Further knowledge is needed about how and why clinicians prescribe medications.