Background The Offender Personality Disorder (OPD) Pathway, a joint health and criminal justice initiative across England and Wales, aims to support rehabilitation of individuals with a likely diagnosis of personality disorder. Pathways Enhanced Resettlement Services (PERS) is an OPD service currently operating in five open prisons in England, which aims to support people at high risk of being returned to closed conditions or reoffending in the community after release. We aimed to understand service user and staff experiences of PERS. Methods We conducted semi-structured interviews with ten staff and nine service users. We then conducted a reflexive thematic analysis generating three themes. Results The three themes identified were: (1) A shock to the system, describing the challenges for service users posed by the liminal space of open prison (between higher security conditions and the community); and how in this context PERS might be viewed with suspicion but was for interviewees ultimately a space where they felt valued. (2) We've got some understanding of their journey; staff and service users described PERS staff developing more trusting relationships with service users than non-PERS staff, where service users felt understood and supported, practically and emotionally; and (3) internal states can be real barriers to progression; PERS staff supported service users to understand and overcome barriers, through enabling self-reflection, and tailoring support to times of greater stress, including key milestones such as parole boards or periods of trial leave. Conclusions Staff and service users feel PERS provides support to progress through open prison, through development of positive trusting relationships and individualised support in a challenging context where such support was not otherwise available.