The harnessing of science and technology as forces for sustainable development depends on processes that will ensure the involvement of all appropriate scientific input and expertise in problem identification and response. Scientific excellence and integrity need to be combined with a close dialogue and cooperation with policy-makers and implementers, including full participation by experts with local knowledge in developing countries. In this paper, we suggest some key elements in the development of the necessary new quality assurance, science communication and public policy processes. These include: new institutions and public procedures for the social evaluation of scientific advances; a shift in emphasis from one-way technology transfer to reciprocal learning and capacity building; and a reassessment of the forms and locations of the "centres of excellence" capable of contributing knowledge and judgement needed for sustainability.