Psychotherapeutic supervision exists to support, develop and monitor the practice of counsellors and psychotherapists. This endeavour creates an opportunity for counsellors and psychotherapists to learn and develop their craft and engage in on-going professional development. The establishment of a safe and trusting supervisory relationship enables supervisees to openly reflect on their casework and gain professional and personal insights. Psychotherapeutic supervisors are experienced practitioners, who are motivated to empower their supervisees, share their wisdom and safeguard clients. The question guiding this research was ‘What is the meaning of being a psychotherapeutic supervisor?’ In order to address this question a Heideggerian, hermeneutic phenomenological philosophical and methodological position was taken. Evocative experiences were captured from 22 interviews with 14 experienced psychotherapeutic supervisors who practised in Northern Ireland and the Republic of Ireland. The analysis of the stories borrowed from participants illuminated the Phenomenon of Responsibility. This phenomenon manifested in unique yet common human experiences in terms of Responsibility as being-true and being-untrue ,Responsibility as leaping-in and leaping-ahead, and Responsibility as existing-resolutely. This study offers the finding that an enduring meaning of being a psychotherapeutic supervisor is being-responsible. The view is offered that existential angst pervades psychotherapeutic supervisory relationships and is inter-twined with experiences of heightened responsibility. The participants’ stories have revealed that the experience of responsibility pervades the world of psychotherapeutic supervision. Being-responsible was an inescapable experience for these psychotherapeutic supervisors. It is contended that responsibility is a hidden yet influential aspect of being a psychotherapeutic supervisor which if unconcealed could be of benefit to the supervisory endeavour. It is argued that the phenomenon of responsibility can be rendered intelligible, in the world of psychotherapeutic supervision, by moving outside of the confines of epistemologies that focus on theories about responsibility or prescribed ethical guidelines and instead, by uncovering and dwelling in the day to day lived experience of being-responsible when being in human to human relationships.