Childhood maltreatment (CM), including emotional, physical, and sexual abuse and emotional and physical neglect, is associated with severity of borderline personality disorder (BPD). However, knowledge on the impact of CM on treatment response is scarce. The authors investigated whether self-reported CM or one of its subtypes affected treatment retention, depressive symptoms, and impulsivity throughout short-term intensive dialectical behavior therapy (I-DBT) in 333 patients with BPD. Data were analyzed with linear and logistic regressions and linear mixed models, using a Bayesian approach. Patients who reported childhood emotional abuse had a higher dropout rate, whereas it was lower in patients who reported childhood emotional neglect. Emotional neglect predicted a greater decrease of depressive symptoms, and global CM predicted a greater decrease of impulsivity. The authors concluded that patients with BPD who experienced CM might benefit from I-DBT in specific symptom domains. Nonetheless, the impact of emotional abuse on higher dropout needs to be considered.