Lean Thinking was originally developed by Toyota in the 1950s as an improvement approach to reducing non-value-adding activity and improving flow within a system. Its use in healthcare is becoming increasingly common although there is little published information on its formal application to Emergency Departments in the UK. With increasing financial pressures, high service demand and target pressures, Lean offers a potential approach to maintaining a high-quality efficient clinical service for patients and staff. Using Value Stream mapping, a tool originally developed for manufacturing, we identified over 300 instances of waste and potential improvements in processes within the majors area of our department. This work allowed us to reduce the time to initial assessment and has highlighted a number of projects that are now being taken forward with directorate backing. With the support of healthcare leaders and managers who embrace the Lean philosophy, Lean Thinking offers huge potential for identifying waste and Value Streams leading to improvements in quality of care in the emergency department.