This paper considers the potential for collaborative patient and public involvement in the development, application, evaluation, and interpretation of patient-reported outcome measures (PROMs). The development of PROMs has followed a well trodden methodological path, with patients contributing as research subjects to the content of many PROMs. This paper argues that the development of PROMs should embrace more collaborative forms of patient and public involvement with patients as research partners in the research process, not just as those individuals who are consulted or as subjects, from whom data are sourced, to ensure the acceptability, relevance, and quality of research. We consider the potential for patients to be involved in a much wider range of methodological activities in PROM development working in partnership with researchers, which we hope will promote paradigmal evolution rather than revolution.