The unsustainability of the present trajctories of technical change in sectors such as transport and agriculture is widely recognized. It is far from clear, however, how a transition to more sustainable modes of development may be achieved. Sustainable technologies that fulful important user requirements in terms of performance and price are most often not available on the market. Ideas of what might be more sustainable technologies exist, but the long development times, uncertainty about market demand and social gains, and the need for change at different levels in organization, technology, infastructure and the wider social and institutional context-provide a great barrier. This raises the question of how the potential of more sustainable technologies and modes of development may be exploited. In this article we describe how technical change is locked into dominant technological regimes, and present a perspective, called strategic niche management, on how to expedite a transition into a new regime. The perspective consists of the creation and/or management of nichesfor promising technologies.