The medical profession has been subject to increasing levels of specialisation over the last century, with the more recent growth of sub-specialisation since the Second World War. There has been a robust body of research that has attempted to predict and describe the fields of specialty to which medical graduates will gravitate. But there has been far less attention to the experiences of those who are in the process of, or who have completed the transition into particular specialties, and little attention or none of any depth, to those who have specialised in Public Health Medicine. This research aims to explore the experiences of Public Health Physicians who are currently in the process of, or who have already made the transition from clinical to one form of non-clinical health practice. This will be achieved through in-depth interviews with already qualified Public Health Physicians as well as those who are in training programmes. Attempts will also be made to recruit doctors who have withdrawn from Public Health training programmes.