Psychotherapeutic treatments of borderline personality disorder (BPD) often focus on severe behavioral problems. Until now, few techniques have been developed to specifically address low self-esteem in BPD. We developed a 6-session psychoeducative group therapy module to treat low self-esteem in BPD patients. After developing and piloting the therapy module, a controlled outpatient pilot study was performed. Nineteen female BPD patients participated in the group module after discharge from an inpatient DBT program. Twenty-four female BPD patients served as controls. Outcome was assessed by different self-esteem measures. Results showed a greater improvement in self-esteem in the intervention group. The findings suggest that the therapy module is an effective adjunctive treatment in increasing self-esteem in BPD.