Purpose The purpose of this research is to focus on a hospital Division of Diagnostics and Clinical Support (150 medical, 1,975 non-medical staff) and how systems were enhanced through lean principles application to facilitate quality and performance improvement. Design/methodology/approach An action research methodology was adopted. The research involved: review of available performance and quality improvement literature; identification of the systems that required improvement; adoption and implementation of new working methods. Findings The results were recognised as being beneficial to all parties, especially the patients! Staff recognised the need for change; the process transformation was actually welcomed. Patient waiting times reduced from 26 to 13 weeks. Fast-track/“query cancer” service for out-patients now within ten days; the majority of in-patients receive imaging within 72 hours. Ultimately, patients are diagnosed faster and treatment commences earlier. Departmental managers can effectively manage capacity to meet demand because they now understand the waiting “profile”. Research limitations/implications The methodology applied was appropriate, generating data to facilitate discussion and from which to draw conclusions. A perceived limitation is the single case approach; however, Remenyi et al. argue that this can be enough to add to the body of knowledge. Practical implications Guidelines indicating “What went well?” and “What could have gone better?” were produced. These centred on the practical application aspects. The implementation methodology developed is being used elsewhere within the same hospital group. Originality/value The paper demonstrates that the application of improvement techniques, such as “Lean”, can focus efforts to improve performance. This is of value to those working in the UK healthcare and wider public sector.