This paper argues that international technology transfer can play a major role for poverty alleviation, environmental sustainability and the the Millennium Development Goals. At present, there are economic, social and legal (rather than technical) barriers preventing the transfer of environmentally sound technology (EST) from a wider use in international regimes. Removing these barriers requires greater political and regulatory efforts both domestically and internationally.To enable EST transfer requires:improved domestic market conditions such as removal of negative subsidies and barriers to foreign investmenttargeted fiscal incentives law reforms favouring sustainable production and use of energyThere is no realistic perspective for international EST transfer as long as it is disadvantaged domestically. A coherent EST transfer regime is only possible through greater governmental intervention at the national and international level, including: environmental regulationsnational systems of innovationcreating an enabling environment for ESTSuch intervention should include effective public-private partnerships, both within and between States. Partnerships, if guided by law, could ensure EST innovation more efficiently than purely State-driven or market-driven EST transfers.In search for a model, the EST transfer regime under the Vienna Ozone Layer Convention and the Montreal Protocol deserves recognition. For example, the clean development mechanism under the Kyoto Protocol allows for considerable scope for EST transfer. The potential of EST transfer for climate change and for meeting the Millennium Development Goals has yet to be realised. [adapted from author]