Therapeutic relationships play a central role in maintaining a positive social climate in forensic settings. The interpersonal difficulties characteristic of Borderline Personality Disorder, alongside the secure environment of forensic wards, can make  developing  positive  therapeutic  relationships  with  this  patient  group  challenging. Qualitative interviews aimed to explore how ward staff understand and experience the interaction of interpersonal relationships and social climate when caring for patients with Borderline Personality Disorder on forensic wards. Interviews with 11 staff members working across UK forensic inpatient settings were analysed using Ref lexive Thematic Analysis and reported following COREQ guidelines. Six interrelated themes were generated; three describe relational cycles that occur between ward staff and patients with Borderline Personality Disorder and three describe systemic factors that inf luence the context in which ward staff operate. From these themes, an integrative model was developed to summarise how factors in the wider forensic system and the interpersonal relationships between staff and patients with Borderline Personality Disorder in forensic wards inf luence one another, affecting staff experiences of the social climate of forensic settings. The model illustrates how complex cycles within the therapeutic relationships with staff and patients with Borderline Personality Disorder can interact with systemic inf luences in the wider forensic context to inf luence staff experiences of forensic settings. Clinical implications of the model are discussed, offering recommendations for improving therapeutic relationships and the social climate on forensic wards caring for patients with Borderline Personality Disorder, to better support staff and patient wellbeing.