Nanotechnologies are a controversial topic, as they seem promising but also cause concern. Previous research has highlighted the potential link between nanotechnologies and other hazardous technologies. The aim of this research was to analyse the discourse on this topic by three groups of participants: laypersons, scientists and environmentalists. Thirty-four people (13 laypersons, ten scientists and eleven environmentalists) were interviewed using a semi-structured interview. Lexical and thematic analyses showed that scientists engage in explanatory discourse and perceive fewer risks than laypersons and (...) environmentalists. The latter two groups describe applications and list the main actors in the development of nanotechnologies. Environmentalists are significantly more likely to make spontaneous associations with other technologies, such as electromagnetic waves, and perceive more risks than the other two groups. Contrary to our expectations, laypersons make fewer associations with biotechnologies than experts or environmentalists. The results are discussed in terms of the interest of a qualitative approach to uncovering new objects spontaneously associated with nanotechnologies, as well as in terms of a risk governance framework. (shrink)