In public health working in a less medical and more preventative way by focussing on the wider determinants of health, inter-sectoral collaboration, and evidence based practice have been advocated as ways to raise the health status of the population. In recent years, the idea of contact with nature to enhance health has come to the fore as one way to tackle current public health challenges: for example, diabetes, overweight and obesity, chronic liver disease, hypertension and mental health problems. Yet little is known about how this idea has diffused through the interdependent figurations of researchers, policy makers and into use through the actions of people in local organisations. The processes connecting these interdependent figurations are complex and, in the case of contact with nature, are not well understood. This is the research problem this thesis seeks to address, that is to say, the evidence into action process of an idea. The theoretical perspective of Norbert Elias is used throughout the thesis to analyse the diffusion process of the idea. Elias’s work is concerned with long term processes in human history; in adherence with his approach to sociological inquiry a historical context going back more than three generations provides the backdrop for the empirical work. An examination of the context illuminated the significance of the decade of the 1970s onwards to the present use of the idea of contact with nature in public health; notably the shift in discourse about hazards, risk and threats from nature to one of health enhancement. Norbert Elias’s own thinking and discourse about contact with nature to enhance health is used as a touchstone for the analysis. The empirical data in the thesis is generated through mixed methods, principally bibliometrics and content analysis, to reveal the diffusion and development of the idea over time and to show the way that the idea is framed when used by researchers, policy makers and by people within organisations. An Eliasian approach to case study methodology is utilised. Sub-study 1 revealed that empirical research literature about the idea emerged in the 1970s and that the number of publications per annum increased year on year until 2005. The empirical research was generated by researchers located across several continents and from different disciplines. Early researchers into the idea investigated the psychological benefits whilst latterly epidemiological studies have come to the fore. Sub-study 2 showed that the idea was taken up widely by policy makers in four government departments in England from 2000, with a peak in 2011. There were more references to the idea in the policy documents of the Department for Environment, Food and Rural Affairs than other government departments; the references of this department took an ecosystem services stance. Sub-study 3 showed that during July to October 2013 and within Greater Manchester, 36 organisations were providing and/or promoting activities which involved the idea of contact with nature on their websites. Of these 36 organisations, 16 (44%) were conservation/wildlife based agencies whose use of the idea included the pursuit of their own agendas and purposes. ix An analysis of the results, using the theoretical perspective of Norbert Elias, shows the involvement of many figurations of interdependent individuals, and the long term, largely unplanned, and non-linear character of the diffusion process. The empirical findings reflect the transdisciplinary nature of the research, inter-sectoral collaboration across government departments within policy, and the adoption of the idea outside of the traditional health service. People and thinking from the environment sector have greatly influenced the diffusion and development of the idea, and their involvement has widened the scope and form of public health action.