Background: Clozapine has been reported to be effective in diminishing violence toward others in psychotic patients. This article describes the impact of clozapine on severe self-mutilation among patients with the dual diagnoses of borderline personality disorder and persistent psychoses. Method: Seven subjects known to the authors were selected for careful chart audits. These subjects had been admitted to 2 state psychiatric hospitals owing to severe self-mutilation and/or violence and subsequently treated with clozapine. A mirror-image design anchored to the start date of clozapine treatment and extending in either direction to a maximum of I year was used to extract data. Data extracted included incidents of self-mutilation (restraint), seclusion, the as and when needed (p.r.n.)use of medications, injuries to staff and peers, hospital privileges, and Global Assessment of Functioning (GAF) scores. Results: The subjects were all white women with a mean age of 37 years. All subjects carried DSM-III-R or DSM-IV borderline personality disorder diagnoses and an Axis I disorder diagnosis. They had received trials of several psychotropic agents, often in combination and mostly without benefit. After clozapine treatment, there were statistically significant reductions in incidents of self-mutilation (restraint), seclusion, the use of p.r.n. antianxiety medications, and injuries to staff and peers. These subjects received higher levels of hospital privileges, and their GAF scores nearly doubled following clozapine treatment. Four subjects were subsequently discharged from hospital. Conclusion: These preliminary but nonetheless favorable results suggest that clozapine deserves careful consideration for a controlled study in patients with borderline personality disorder and psychoses, especially if the clinical issues include severe self-mutilation, aggression, and violence. Until such studies are done, the risk-to-benefit ratio of clozapine treatment needs to be carefully evaluated on an individualized basis in such subjects.