A comprehensive updated guide to the benefits of patient and public involvement in quality improvement projects in healthcare settings and how to implement it effectively. It covers the benefits of patient and public involvement in quality improvement, which include offering different perspectives to those of staff, creating a service more aligned to patient's needs, helping inform choice, engaging people with services available, responding to local needs, and developing appropriate indicators to help improve care. It also looks at the legal requirements for patient and public involvement in quality improvement projects, how to carry out an impact assessment, and provides an overview of the quality improvement cycle. A number of quality improvement projects are included as case studies illustrating patient and public involvement through the application of various quality improvement methods. This guide is aimed at those involved in quality improvement in healthcare organisations, and although written for use in healthcare, much of this guide can be adapted for use in social care settings.