Contrary to common clinical perceptions, individuals with personality disorders attempt and commit suicide at nearly the same rate as individuals with major depression. In particular, those with borderline personality disorder are at high risk for suicidal behavior and nonsuicidal self-injury. Yet there is significant controversy surrounding the diagnosis of borderline personality disorder in terms of its existence, its definition and symptom structure, its Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) axis location, and its importance as a contributing factor to suicidality and nonsuicidal self-injury. Furthermore, both suicidal and nonsuicidal self-harm is prominent in borderline personality disorder. There is often confusion between suicidal and nonsuicidal self-injury with one sometimes mistaken for the other. Nonsuicidal self-injury is sometimes met with hospitalization, because it is viewed as life threatening. Alternately, the potential lethality of suicidal behavior is underestimated, because it occurs in the context of multiple low lethality self-harm behaviors. It is possible to view these behaviors as distinct yet on a spectrum in borderline personality-disordered patients. With respect to treatment of self-injury in personality disorders, some recent pharmacotherapy trials have been conducted, though efficacy is often unclear. Findings with respect to psychotherapy, particularly dialectical behavior therapy, a form of cognitive behavioral treatment, are promising.