Borderline personality disorder (BPD) is a relatively new concept which has received much attention recently. In ICD-10, emotionally unstable personality disorder, is subcategorised as impulsive type and borderline type. According to DSM IV diagnosis of BPD requires at least five out of nine features. Antipsychotics is effective in reducing affective instability, anger and psychotic symptoms. Beneficial effects were found with mood stabilisers such as semisodium valproate, lamotrigine and topiramate, but not carbamazepine. Psychological treatment is considered as first line treatment for borderline patients but the evidence is not extensive for most of the therapies except for dialectical behavioural therapy.