CEDAR contributed to plans for establishing community diagnostics centres in South Wales. We carried out a rapid review of the potential benefits associated with improving access to diagnostic tests and imaging, illustrating our findings by focusing on some specific clinical pathways. Comparisons were made with similar initiatives elsewhere, and we identified risks and assumptions associated with the new ways of working. We used logic modelling to consider the wider implications of changes to the service delivery model, including the possible economic and financial impact. Our report to Cardiff and Vale University Health Board was informed by published evidence on the impact that waiting for a diagnosis can have on patients’ health and wellbeing.