Since the early 1990s there has been a growing interest in using the results of research to improve health and health services. This work has been taken forward under titles such as evidence-based practice, clinical effectiveness and implementation of research findings. This report explains lessons learned from the King's Fund programme Promoting Action on Clinical Effectiveness (P.A.C.E.). Based on a mid-term review of the programme, the report describes the progress made in 16 projects around the country where NHS staff are working to turn evidence into everyday clinical practice. The report reveals that while change in practice is achievable, work to promote clinical effectiveness is complex. Early results from local projects have brought into sharper focus a number of challenges that will need resolving if work on clinical effectiveness is to have a lasting influence on health and health care.