Evidence for mentalisation-based therapy (MBT) is increasing in relation to the treatment of personality disorder. Individuals with personality disorder are over-represented in inpatient, forensic and forensic inpatient mental health services. This study explores MBT within a forensic setting as an intervention designed to moderate deficits linked to violence and to improve adaptive coping. Interpretative phenomenological analysis was conducted on interviews with four patients who completed MBT at a high-secure hospital. Findings suggest that MBT-enhanced participants' mentalising which had a positive impact upon their capacity to manage their behaviour and emotions. MBT further enabled participants to process past experiences of violence and develop some degree of empathy for others, which led to a trend in abstinence from risk behaviours. Findings contribute a secure inpatient perspective on the experience of MBT and to MBT clinical outcomes.