A childhood history of sexual or physical abuse is highly prevalent in borderline personality disorder (BPD) and is associated with self-destructive behavior in clinical and nonclinical samples. Viewing BPD as a "high risk" disorder, we asked if childhood abuse was a risk factor for adult suicidal behavior or if it was related to other known risk factors for suicide in BPD. A semistructured Abuse History was obtained in 61 criteria-defined BPD patients, who were characterized by structured interviews and self-reports for Axis I disorders, Suicide History, BPD severity, hopelessness, impulsivity, impulsive-aggression, and antisocial traits. Occurrence and severity of childhood sexual abuse, but not physical abuse, predicted adult suicidal behavior independent of other known risk factors. The odds of a sexually abused patient attempting suicide in adulthood was over 10 times that of a patient who was never sexually abused. Given a history of childhood sexual abuse, the risk of adult suicidal behavior in BPD was increased by antisocial traits, severity of BPD, hopelessness, or comorbid major depressive episode (MDE).