Background In England, the National Offender Management Service and the NHS have come together to try and improve management and treatment of offenders with personality disorder by developing a pathways approach to assist high‐risk male offenders with severe personality disorder. Aim The aim of the study is to investigate service user and staff perceptions of change in this pathway. Methods Semi‐structured interviews were conducted with 16 prisoners and 16 staff in one unit in a London‐based personality disorder pathway. The four core questions were as follows: (1) what changes do you think have occurred?; (2) what do you think helped make these changes?; (3) how do you think this helped change?; and (4) what hindered positive change? Thematic analysis was applied to the narratives. Results Prisoners and staff separately reported similar changes, each observing that prisoners became less anti‐authority, improved their self‐understanding, developed feelings of self‐worth and increased their optimism about change. There was similar consensus on what they thought had brought about change – primarily development of trusting relationships. These allowed a psychological perspective on understanding prisoners' behaviour. Maintenance of this approach was seen as demanding, with barriers including ‘security restrictions’ curtailing purposeful activities, visits and community contact and ‘stigmatising beliefs about personality disorder’ in the wider prison. Implications for Practice Findings suggest that shared goals and progress are achievable. Difficulties in sustaining these will require a range of solutions, but wider support from the prison is essential to containing hostility to such prisoners and specialised work and ensuring the provision of purposeful activity. Copyright © 2017 John Wiley & Sons, Ltd.