Science-based biomedical innovation is a complex process that calls on cooperative activity between a number of public and private-sector organisations and professions, such as the role of physicians and hospitals in the conduct of clinical trials. Basing itself on the literature that discusses innovation as the outcome of user-producer interaction, which has been concerned mainly with manufacturing innovations, this paper discusses the impact of end-users, ie patients, on the process of biomedical innovation. Primary evidence of the involvement of user groups in a number of current developments is discussed, and the prospects for generalising such findings is analysed.