This special issue of the CIPAST newsletter was prepared by Nicolas Baya Laffite at INRA/TSV. It provides a summary of participatory processes in nanotechnology governance in countries where they have developed significantly as a result of political initiatives, namely in the United States, in the UK and in other Member States of the European Union. The newsletter draws on the CIPAST database, the 2007 final report of the Nanotechnology Engagement Group (NEG), and extensive internet research. Our first aim is to give access to data as complete as possible – although not exhaustive – on individual participatory experiences in nanotechnology. The gathering of this information allows to put these individual experiences into perspective and to open a discussion on the roles of public participation, so far in different national and regional political contexts. A table of contents can be found on page 3 of this newsletter.