This paper summarizes the work on the social dimension conducted within the EU FP7 SiteChar project. The most important aim of the research was to advance public awareness and draw lessons for successful public engagement activities when developing a CO2 storage permit application. To this end, social site characterization (e.g. representative surveys) and public participation activities (focus conference) were conducted at two prospective Carbon Capture and Storage (CCS) sites: an onshore site in Poland and an offshore site in Scotland. The research consisted of four steps over a time period of 1.5 year, from early 2011 to mid-2012. The first step consisted of four related qualitative and quantitative research activities to provide a social characterization of the areas: desk research, stakeholder interviews, media analyses, and a survey among representative samples of the local community. The aim was to identify:-stakeholders or interested parties;-factors that may drive their perceptions of and attitudes towards CCS. Results were used to as input for the second step, in which a new format for public engagement named ‘focus conferences’ was tested at both sites involving a small sample of the local community. The third step consisted of making available generic as well as site-specific information to the general and local public, by:-setting up a bilingual set of information pages on the project website suitable for a lay audience;-organizing information meetings at both sites that were open to all who took interest. The fourth step consisted of a second survey among a new representative sample of the local community. The survey was largely identical to the survey in step 1 to enable the monitoring of changes in awareness, knowledge and opinions over time. Results provide insight in the way local CCS plans may be perceived by the local stakeholders, how this can be reliably assessed at early stage without raising unnecessary concerns, and how results of this inventory can be used to develop effective local communication and participation strategies. In future project development, if any, these results can be used to start up and inform the process of information provision and public engagement.