Patients with borderline personality disorder (BPD) are overrepresented in compulsory inpatient care for suicide-protective reasons. Still, much evidence indicates negative effects of such care, including increased suicide risk. Clinical guidelines are contradictory, leaving clinicians with difficult ethical dilemmas when deciding on compulsory care. In this study, we analyse the arguments most commonly used in favour of compulsory care of BPD patients, to find out in what situations such care is ethically justified. The aim is to guide clinicians when deciding on compulsory care for BPD patients and reduce the use of potentially harmful care. The arguments analysed are (a) the patients lack decision competence, (b) the patients lack authenticity, (c) compulsory care saves the patient from suicide, (d) compulsory care safeguards against litigation, complaints, or doctor's anxiety, (e) compulsory care is a practical solution in emergencies, and (f) it is better for the caregiver to ‘err on the safe side’. We conclude that compulsory care is not ethically justified in most cases unless the clinician has probable reason to believe that the patient lacks decision capacity by suffering from a severe mental co-morbidity and stands to benefit from such care.