Stakeholder risk and benefit perceptions and attitudes towards a technology matter for the societal response to these technologies. This is especially the case for technological innovations where the public has no direct experience with the technology and its applications. In such cases, expert views are the main source for public opinion formation. Stakeholder risk and benefit perception, and their effect on attitudes towards a new technology (nanotechnology) and its applications were examined in two studies. In a survey, the effect of risk and benefit perception on attitudes to nanotechnology in specific application domains (energy, water, food and medicine) was examined. While risk and benefit perception predicted much of the variance in attitude, experts were more positive about medicine applications and more negative about food applications than could be explained through risk and benefit perception. In the second study, expert focus groups were asked for reasons why food and medicine were seen as more negative and positive than based on the risk and benefit perceptions as measured in the survey. For medicine, the urgency and unique potential of nanotechnology was seen as a reason as why this domain was liked more. For food, the high level of uncertainty about risk assessment and about exposure of consumers and the lack of urgency in applying nanotechnology to food was seen as a reason this domain was liked less. In addition, experts voiced concern about potential negative public response to food applications as reasons for their negative attitude. These results thus suggest that both risk and benefit perception consist of multiple dimensions that require further exploration.