One of the ways in which researchers, policy makers and practitioners routinely characterise illicit drug use is through a taxonomy of two paired conditions, the negative state of 'chaos' and the positive state of 'order' in the form of 'stability.' In this article, we explore some of the ways in which this taxonomy operates in public discourse on illicit drug use. Google searches were conducted in order to gather a corpus of Australian, United Kingdom and United States materials making use of notions of chaos and stability in discussing illicit drug use. The chaos/stability pairing was identified in a large number of materials, including government policy documents, internet web sites for drug related services, newspaper articles and research papers. Drawing on the work of Michel Foucault and Michel Serres, we argue that references to chaos and stability within public discourse produce at least three different ontological registers in which drug users are positioned: (1) the drug user as chaotic, (2) the drug using way of life as chaotic and (3) drug use activities as chaotic. These registers produce different semantic effects in that each locates the 'problem' of chaos differently and invokes it for different political and regulatory ends. Further, we argue that the taxonomy serves mainly to affirm the illegitimacy of injecting drug use by establishing and policing boundaries between the ostensibly unproductive, disorderly lives of drug users and the 'normal,' orderly and productive lives of non-injecting drug users. In concluding, we question the adequacy of chaos, as conventionally defined, in accounting for the circumstances and actions of drug users, and canvass alternative ways of viewing chaos that might offer useful critical tools for drugs research, policy and practice.