AbstractDemand may act as a stimulus to innovation. New products and processes may be launched into an established market, where demand can be demonstrated to exist for something that fulfils the functions offered by the innovation. However, such a market may not exist, especially for radically new technologies. Or the concept of selection environment may be more appropriate in analysing the unfolding processes.The role played by demand in the origin, commercialisation and diffusion of biotechnology is explored. In this case, neither public procurement nor commercial markets provided a ‘demand pull’. The innovating firms played an active role in stimulating and shaping both market and non-market elements of the selection environment, and in enlisting intermediate agents to assist the process.