In this study, we describe the types and amounts of psychiatric treatment received by a well-defined sample of borderline personality disorder (BPD) inpatients, and compare these parameters with those of a group of carefully diagnosed personality-disordered controls. Finally, we assess the risk factors associated with a history of intensive, high-cost treatment, which we defined as having had two or more prior psychiatric hospitalizations. The treatment histories of 290 borderline inpatients and 72 axis II controls were assessed using a reliable semistructured interview. All nine forms of treatment studied except electroconvulsive therapy (ECT) were common among borderline patients (36% to 96%). In addition, a significantly higher percentage of borderline patients than axis II controls reported a history of individual and group therapy, day and residential treatment, psychiatric hospitalization, participating in self-help groups, and taking standing medications. They were also significantly younger when they first entered individual therapy and began to take standing medications. In addition, borderline patients spent more time than axis II controls in individual therapy and psychiatric hospitals, and were on standing medications for a significantly longer period of time. They also reported a significantly higher number of psychiatric hospitalizations, lifetime number of standing medications, and number of psychotropic medications taken at the same time. In addition, we found a highly significant multivariate predictive model for multiple prior hospitalizations. The six significant predictors were age 26 or older, a history of quasi psychotic thought, lifetime number of self-mutilative efforts and suicide attempts, a childhood history of reported sexual abuse, and an adult history of being physically and/or sexually assaulted. Taken together, these results confirm clinical impressions concerning the high rates of mental health services used by borderline patients. They also suggest that particularly high rates of costly inpatient treatment are associated with a complex admixture of older age, BPD symptoms in the cognitive and impulse realms, and traumatic life experiences occurring in both childhood and adulthood.