One of the primary facets of borderline personality disorder (BPD) is behavioral dysregulation, a wide array of behaviors that are difficult to control and harmful to the individual. The purpose of this study was to explore the association between BPD and a variety of dysregulated behaviors, some of which have received little empirical attention. Using a large sample of individuals diagnosed with anorexia nervosa, 41 individuals diagnosed with BPD were compared to the rest of the sample on the presence of dysregulated behaviors using logistic regression analyses. Anorexia nervosa subtypes, age, and other Cluster B personality disorders were used as covariates. Results support an association between BPD and alcohol misuse, hitting someone/breaking things, provoking fights/arguments, self-injury, overdosing, street drug use, binge-eating, impulsive spending, shoplifting/stealing, and risky sexual behaviors. Differences between dichotomous and continuous measures of BPD yielded somewhat different results. Information on co-occurring anorexia nervosa and BPD was generated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)