There has been considerable momentum within the NHS over the last 10 years to develop greater patient and public involvement (PPI). This commitment has been reflected in numerous policy initiatives. In patient safety, the drive to increase involvement has increasingly been seen as an important way of building a safety culture. Evidence suggests, however, that progress has been slow and even more variable than in health care generally. Given this context, the paper analyses some of the key underlying drivers for involvement in the wider context of health and social care and makes some suggestions on what lessons can be learned for developing the PPI agenda in patient safety. To develop PPI further, it is argued that a greater understanding is needed of the contested nature of involvement in patient safety and how this has similarities to the emergence of user involvement in other parts of the public services. This understanding has led to the development of a range of critical theories to guide involvement that also make more explicit the underlying factors that support and hinder involvement processes, often related to power inequities and control. Achieving greater PPI in patient safety is therefore seen to require a more critical framework for understanding processes of involvement that can also help guide and evaluate involvement practices.