The recent special issue of the International Journal of Drug Policy on the state of ethnography in the drug field (Volume 13.4) provides a timely reminder of the difficult relationship between different research disciplines and traditions in a field increasingly scattered with examples of what might be termed as ‘multidisciplinary’ research. In this response, I consider some of the issues raised by the authors in the special issue, from my perspective as an epidemiologist (with a background in experimental psychology) in the Australian drug research field, focusing on their application to questions around illicit drug surveillance. Many of the papers in the special issue present a critique of epidemiology (both in the drug field as well as relating to health issues more broadly; see Maher, 2002, for example) that is both epistemological and methodological. Quantitative epidemiological research has largely been operationalised methodologically through ‘observational’ studies (e.g. case /control and prospective cohort studies, along with the collection and compilation of routine statistics on health-related states) with the emergence more recently of study technologies such as population-based randomised controlled trials (RCTs). The theoretical focus of epidemiology reflects its movement away from its historical roots to the margins of biomedicine (inhabited also by some public health practice) with the majority of studies concerned with the description of individualised risk factors for states of health and/or disease from a so-called ‘positivist’ perspective (a point noted by Bourgois, 2002). The criticism aired by Maher and others is mirrored within the broader field of epidemiology itself, where reaction to the excessive focus on methodological rather than theoretical, sophistication has led to the emergence of research designed to embed epidemiological findings within wider social and political contexts (Berkman & Kawachi, 2000; Krieger, 1994). In general, I would argue that illicit drug epidemiology, in contrast to mainstream epidemiology, does not suffer from excessive methodological sophistication (this is not the case with legal drugs such as alcohol and tobacco). In fact, all too often illicit drug epidemiology relies upon surveys of convenience samples of drug users (recruited through, for example treatment or other service attendance). While these types of survey have produced important and useful findings, they are often treated as though they represent random samples of illicit drug users, thereby allowing statistical generalisation to what, conceptually, is assumed to be a homogenous population of illicit drug users (cf. Bourgois, 2002). From the perspective of mainstream epidemiology, such methods are open to the same sorts of criticisms that have been applied to ethnography (i.e. the problem of generalisation). Indeed, recognition of the limitations of such quantitative data has led to the development of what I would term multi-method research. Owing more to a tradition of problem-oriented research (Bammer, Beers, & Patel, 1999), or indeed market research, than any real ‘multidisciplinarity’ (which I interpret to mean more than methodological integration to include theoretical and epistemological integration), some of the most pertinent examples of this kind of work in drug epidemiology relate to the monitoring and detection of trends in drug use and harm (Griffiths, Vingoe, Hunt, Mounteney, & Hartnoll, 2000; Hando, O’Brien, Darke, Maher, & Hall, 1997). While perhaps lacking in the methodological sophistication of mainstream epidemiology, illicit drug epidemiology shares its theoretical and interpretive poverty (as noted by Krieger, 1994). I regard Maher’s (2002) criticism of illicit drug epidemiology as relating primarily to a lack of measurement sensitivity (e.g. the case of her ‘backloading’ example) that has led to overly * Present address: Turning Point Alcohol and Drug Centre, Inc., 5462 Gertrude St Fitzroy, Vic. 3065, Australia. Tel.: /61-8413-8413; fax: /61-9416-3420. E-mail address: pauld@turningpoint.org.au (P. Dietze). International Journal of Drug Policy 14 (2003) 131 /135