We compare self-injurers with and without Borderline Personality Disorder (BPD). We use established diagnostic interviews and self-report measures. Adults with BPD reported more severe, frequent and versatile self-injury. NSSI with BPD had higher rates of anxiety disorders, compared to NSSI without BPD. NSSI with BPD had more severe suicidal ideation, compared to NSSI without BPD.