Anticonvulsants are showing to be helpful in the treatment of Borderline Personality Disorder and are widely used in clinical settings, although few studies have been published and their role in different borderline patients is not completely outlined. Gabapentin pharmacologic profile and its documented efficacy in anxiety disorders and drug abuse withdrawal were the basis for this open label multicenter six-month follow-up trial in borderline patients not enough responsive to previous therapies. DSM-IV Borderline Personality diagnosis was confirmed by the Diagnostic Interview for Borderlines-Revised. Outcome measures were changes in scores on Hamilton Anxiety Rating Scale, Young Mania Rating Scale, Beck Depression Inventory, Barratt Impulsivity Scale and Clinical Global Impression Scale of Severity and Improvement. A global improvement, especially in anxious and depressive symptomatology, was observed; no adverse events were reported. Gabapentin showed to be efficacious and safe in Borderline Personality Disorder's treatment.