BACKGROUND: This article explores the recreational use of diverted dexamphetamine, a pharmaceutical stimulant, amongst a social network of young adults (aged 18-31 years) in Perth, Western Australia (WA). Prior epidemiological research indicates that there are high levels of dexamphetamine prescription, and use of diverted dexamphetamine, in this jurisdiction. Little research exists on the social contexts of diverted dexamphetamine use in Australia or overseas. METHODS: Ethnographic fieldwork was conducted over 18 months amongst a network of approximately 60 young adults who regularly used psychostimulants. Data collection involved participant observation conducted in natural settings including nightclubs and private parties. In-depth interviews were also conducted with 25 key contacts which explored drug use histories and themes emerging from fieldwork. RESULTS: The use of diverted dexamphetamine, or 'dexies', was prevalent amongst the social network and integrated into local drug practices. The paper explores the ways in which dexamphetamine use is rationalised, negotiated and represented in the context of the use of alcohol and other psychostimulants such as methamphetamine and ecstasy. Two key aspects are emphasised. First, dexamphetamine use is seen as insignificant by network members and is positioned as 'safer' in relation to the use of other drugs by virtue of its pharmaceutical status. Second, dexamphetamine plays an instrumental role in facilitating the pursuit of 'controlled pleasure' via the heavy consumption of alcohol and other drugs. CONCLUSION: The findings of the paper have implications for harm reduction policy. In particular, dexamphetamine use facilitates heavy drinking and polydrug use amongst young adults, which may increase the harms associated with such use. Further, current interventions targeting young psychostimulant users, which emphasise their adulterated and illegal nature, may inadvertently contribute to the cultural construction of dexamphetamine as a relatively 'safe' drug.