This paper draws from research commissioned by the Scottish Executive Health Department (SEHD). It provides a case study in the introduction of a new health care worker role into an already well established and "mature" workforce configuration It assesses the role of US style physician assistants (PAs), as a precursor to planned "piloting" of the PA role within the National Health Service (NHS) in Scotland. The evidence base for the use of PAs is examined, and ways in which an established role in one health system (the USA) could be introduced to another country, where the role is "new" and unfamiliar, are explored. The history of the development of the PA role in the US also highlights a sometimes somewhat problematic relationship between P nursing profession. The paper highlights that the concept of the PA role as a 'dependent practitioner' is not well understood or developed in the NHS, where autonomous practice within regulated professions is the norm. In the PA model, responsibility is shared, but accountability rests with the supervising physician. Clarity of role definition, and engendering mutual respect based on fair treatment and effective management of multi-disciplinary teams will be pre-requisites for effective deployment of this new role in the NHS in Scotland.