Emotion dysregulation including a hypersensitivity to emotional stimuli and affective hyper-arousal is a core feature of Borderline Personality disorder (BPD). Previous research in patients with BPD has linked emotion dysregulation to a deficient cognitive inhibition of emotional stimuli. For example, individuals with this disorder showed pronounced difficulties in suppressing emotional distractors in the context of a working memory task (“Emotional Working Memiry Task”). In healthy individuals, a computerized ”Emotional Working Memory Training” (developed by Schweizer, Hampshire, and Dalgleish, 2011) showed a beneficial transfer effect on emotion regulation capacities (reappraisal). The aim of the present project is to investigate whether this Emotional Working Memory Training has an effect on emotion regulation strategies in BPD patients by providing a summative and formative evaluation. Sixty female patients with BPD (aged between 18 to 55 years) are randomly assigned to one of two training conditions: One group ( N=30) performs the Emotional Working Memory Training (dual-n-back-task with emotional audio and visual distractor stimuli), while the other group (control group, N=30) performs a placebo training (Emotional Feature Match Task) on 26 days for 20 minutes daily. Before and after the training, performance on an adapted version of the Sternberg Emotional Working Memory Paradigm (Krause-Utz et al., 2014, “near transfer”) and on an established emotion regulation paradigm (reappraisal paradigm, “far transfer”) are assessed. In addition to behavioral data (e.g., reaction times, errors), psychophysiological variables (electrodermal activity, heart rate), and clinical questionnaires (e.g., self-reported difficulties in emotion regulation and emotion regulation strategies, dissociation, childhood trauma history) as well as  commitment and acceptance of the training are measured.