Although nanotechnologies are considered key technologies that can drive growth-generating innovations in well-saturated markets, worldwide investment in nanotechnologies has to date focused largely on technology-related development programmes and little effort has been expended to research associated risks. As a result, even though prior discourses have sensitized western consumers to potential health-related dangers, solid knowledge on, for example, the toxicological and eco-toxicological risks and unintended side effects of nanotechnology are scarce. This paper therefore presents an overview of the current evidence on consumer knowledge and perceptions of nanotechnology and public engagement with it, with a focus on the US, the UK and Germany. Overall, even though survey data suggest that awareness of the term ‘nanotechnology’ has risen slightly, today's consumers are generally ill informed about its nature and its applications in consumer-related products. Hence, based on our analysis of these data, we argue that early political engagement in the nanotechnology issue – for example, consumer policy options that support consumer interest in the marketing of ‘nanos’– would facilitate objective public discourse.