OBJECTIVE: Borderline Personality Disorder (BPD) is characterized by extreme emotional dysregulation. Dialectical Behavioral Therapy (DBT) is an empirically supported and effective treatment for BPD in adolescents and adults. However, the extent to which exposure to childhood abuse (i.e. physical and sexual abuse) impacts treatment outcomes is not well understood. This open trial investigated the effectiveness of an intensive residential DBT program in reducing emotion dysregulation in adolescents with BPD symptoms, as well as the impact that severity and type of childhood abuse had on treatment outcomes. METHOD: Participants (N = 46) were female-identifying adolescents 13 to 20 years of age enrolled in an intensive residential DBT treatment program. Severity of abuse exposure and abuse subtype (Childhood Trauma Questionnaire, Short Form (CTQ-SF), and difficulties with emotional dysregulation (DERS) were assessed at admission and DERS again after one month of treatment. RESULTS: Bivariate correlation between DERS Total Score and Abuse Exposure Total Score indicated that severity of abuse exposure had a medium positive association with emotion dysregulation at admission. Mixed model ANOVA results showed significant reductions in emotion dysregulation following one month of treatment, with a large effect size. Exploratory analysis testing exposure to different subtypes of childhood abuse as a moderator of treatment effects was non-significant. CONCLUSIONS: Emotion dysregulation showed significant reductions following intensive residential DBT interventions. Reductions were consistent across subtypes of abuse exposure. Implications for the treatment of adolescents with abuse histories and current BPD-related problems, and the relationship between child abuse exposure and emotion dysregulation overall, are discussed.