Nanotechnology has recently been identified with principles of sustainability and with a ‘green’ agenda generally . Some maintain that this green dream of nanotechnology is a rather ephemeral societal phenomenon that owes its existence to the campaign ploys of politics and business. This paper argues that deeper lying societal and cognitive structures are at work here that complement or even substantiate in some sense the seemingly manipulative saying of a greening of nanotechnologies. Taking seriously the concept of ‘green nano’, this (...) paper examines the common ground between sustainability discourse and the discourse of nanotechnology. Green nanotechnology is understood as a boundary concept in which disparate discourses and concepts join together. The primary concern of the paper is to show that nanodiscourse and ecodiscourse share visions of control and of excess. Both ecotechnology and nanotechnology accept and incorporate arguments about limited growth, and each develops strategies of control—be it through a new-found precision in the control of material flows or through greater efficiency in product design. (shrink)