Individuals with borderline personality disorder (BPD) struggle with unbearable emotions that arise out of interpersonal difficulties. Self-harm and suicidal behaviours serve to regulate these emotions and to gain a sense of well-being and control in a treatment context where hospital admissions are avoided by mental health services. Clinician engagement with families may be constrained by their knowing the accepted etiology of the disorder, which includes a causal link with the family environment. Other constraining factors include the negativity of those with BPD toward their family, and their clinicians' diagnostic uncertainty or confusion. This qualitative study explored the experience of families whose close relative with BPD has a long history of self-harm and/or suicide attempts. Family members were found to have chronic and traumatic stress. Family roles and relationships were strained, as were relationships between the family and the mental health system. The findings of this study indicate that treatment for BPD needs to adopt a systemic approach that considers individuals and their significant family relationships, as well as relationships between the family and treatment providers.