Action 98 of the National Drugs Strategy 2001-2008 required the NACD to carry out research on drug misuse among at-risk groups, including prostitutes/sex workers. In response, the NACD undertook this study to explore female and male problematic drug-using sex workers' lived experience of risk, and how the risk environment can mediate the individual’s capacity to reduce the risk of harm. The concept of the risk environment was broadly defined as comprising risk factors that are external to the individual. Thus, the 'environment' encompasses not only the physical space within which drug-using sex workers live and work, but also the social, economic and policy environment.