Scientists’ sense of social responsibility is particularly relevant for emerging technologies. Since a regulatory vacuum can sometimes occur in the early stages of these technologies, individual scientists’ social responsibility might be one of the most significant checks on the risks and negative consequences of this scientific research. In this article, we analyze data from a 2011 mail survey of leading U.S. nanoscientists to explore their perceptions the regarding social and ethical responsibilities for their nanotechnology research. Our analyses show that leading (...) U.S. nanoscientists express a moderate level of social responsibility about their research. Yet, they have a strong sense of ethical obligation to protect laboratory workers from unhealthy exposure to nanomaterials. We also find that there are significant differences in scientists’ sense of social and ethical responsibility depending on their demographic characteristics, job affiliation, attention to media content, risk perceptions and benefit perceptions. We conclude with some implications for future research. (shrink)