The present report represents the nanostudy part of a larger study entitled “Green Technology Foresight about Environmentally Friendly Products and Materials – Challenges from Nanotechnology, Biotechnology and ICT” (Jørgensen et al. 2006). The study wasmade for the Danish Environmental Protection Agency and feeds into recent international trends in developing a stronger innovation perspective to environmental policy, noticeably the EU ETAP (European Environmental technology action plan) process. InDenmark it is related to the development of a Danish environmental technology action plan (forthcoming in summer 2006). The analysis focuses not only on the environmental impact but even more on the dynamics involved in nanotechnology development ofwhich we currently know very little. Applying an innovation economic perspective focus is placed on analysing the direction of the nano search and technology development processes and how environmental issues enter into these. Hereby, the futuretrajectories of nanotechnology development is sought captured, indicating likely long-term perspectives of the Danish nanotechnology development. The content of the report is as follows: What is nanotechnology? Definitions and dynamics. What dointernational findings say on environmental opportunities and risks of nanotechnology? The path creation processes within nanotechnology in Denmark. Focus is on how environmental issues enter into the strategies and search processes of Danish nanoresearchers and related industry. The identification of nanotechnology eco-opportunities more generally and through 6 short case studies. A very wide range of nano eco-opportunities have been identified although most of thse are at a very early andhighly uncertain stage of development. Generally, however, green attention and search rules among Danish nanoresearchers are quite weak, meaning that many eco-opportunities are likely to be neglected and environmental and health risks overlooked.