This qualitative investigation aimed to explore the experiences of eight psychoanalytic psychotherapists' work with clients diagnosed with 'Borderline Personality Disorder' (BPD) in an NHS Community Mental Health Service. Previous quantitative research indicates that working with this client group is challenging and can lead clinicians to harbour negative feelings towards their clients. Few qualitative studies exist focussing on the way in which practitioners cope and manage working with this challenging client group. Interpretative Phenomenological Analysis (IPA) was used to analyse participant interviews. Findings revealed three main themes: a) Recognising The 'Borderline' Signature - referred to the experiential ways in which participants detected the presence of 'BPD'; b) The 'Borderline' Relationship; The Emotional Impact - referred to the strong feelings evoked in the therapist and his/her attempts to manage these intense experiences; c) Struggling Within The Working Context - referred to the impact of working within an impoverished Mental Health Service. In line with previous research, this study revealed inherent difficulties involved in working with 'borderline' clients. However, it also highlighted additional challenges relating to working alongside different frameworks, professional relationships with colleagues and working within an impoverished Mental Health Service. It is hoped that this research will inspire other clinicians to reflect upon the impact of their work.