Dialectical Behavior Therapy (DBT) is now a well consolidated system of treatment for Borderline Personality Disorder (BPD) and for clinical conditions where emotional dysregulation plays an important role both in pathogenesis and in stability over time of dysfunctional phenomena. DBT treatment is made of different modes (individual psychotherapy, skills training, phone calls, team meeting) contributing in different ways to the outcome. What seems very important, in order to better understand the therapeutic process, is to clarify the role and effect of treatment components. Recent research is mainly focused on skills training and, in particular, on mindfulness. Research data show that Borderline subjects have strong difficulties in “being here and now in an accepting and non-judgmental stance”. This is significantly connected to their tendency to be emotionally and behaviorally dysregulated. Consequently, the possibility to modify the vicious circle connecting lack in mindfulness-emotional dysregulation-behavioral dysregulation appears a very powerful, and specific, component of DBT therapeutic method.