Objective: Borderline personality disorder (BPD) is characterized in the DSM by anger. While previous studies have examined various types of externalized aggression and violence among individuals with BPD, we are aware of no investigations of disruptive behaviors perpetrated by patients with BPD in medical settings-the focus of the present study. Method: Using a cross-sectional, consecutive sample of internal medicine outpatients from a resident provider clinic, we surveyed 397 participants regarding 17 disruptive behaviors related to medical personnel and assessed BPD using two self-report measures, the BPD scale of the Personality Diagnostic Questionnaire-4 (PDQ-4) and the Self-Harm Inventory (SHI). Results: A statistically significantly greater proportion of respondents who exceeded the clinical cut-off scores for BPD on both the PDQ-4 and SHI endorsed at least one form of disruptive behavior. However, there were no differences between participants with versus without BPD symptomatology regarding the number of different forms of disruptive behaviors after that initial threshold of one such behavior was reached. Several specific disruptive behaviors were reported more often in those with BPD symptomatology (i.e., yelling, screaming, verbally threatening, and refusing to talk with medical staff as well as talking badly about medical staff to the patients' friends and family). Conclusions: BPD appears to be associated with a greater likelihood of disruptive behaviors in the medical setting, but not physical threat. (Int'l. J. Psychiatry in Medicine 2011;41:355-363)