Many people believe that ordinary citizens should influence scientific and technological developments, but the American public is routinely uninformed about these issues. As a solution, some scholars advocate creating informed public opinions by encouraging citizens to deliberate about the issues. Although this idea is currently widely applauded in the science and technology literature, deliberative outcomes are infrequently measured and the practice of deliberation is routinely criticized in other disciplines. This research contributes to our understanding of the effectiveness of citizen deliberation as a method for increasing public engagement with science. I report data measuring results of deliberation in a national citizens’ technology forum (NCTF) about nanotechnologies for human enhancement. The NCTF was a month-long process involving six groups of 9–15 ordinary citizens who deliberated in different locations across the United States with the goal of reaching consensus about policy recommendations within their groups. I find that structured deliberation generated informed opinions, sometimes meaningful shifts in preferences, and increased trust and internal efficacy among the participants. Nevertheless, the NCTF has important shortcomings, and it is not obvious that consensus conferences should be preferred over other mechanisms for creating informed opinions. Future research is needed to corroborate the findings of this study and to systematically compare outcomes of structured citizen deliberation to other less resource intensive forms of engagement.