BACKGROUND: Pleasure and its pursuit provide the key explanatory frame in this ethnographic analysis of temazepam injection among a set of drug injectors who enthusiastically embrace high-risk practices. The foregrounding of pleasure challenges key assumptions of harm reduction: namely, the 'rational' subject and the privileging of health as a universal good. In this paper I problematise the concepts of pleasure and conventional understandings of rationality. Interrogating these concepts through the actions and accounts of temazepam injectors, I argue that the model of the subject implicit in harm reduction does not sufficiently account for their everyday social practices. METHODS: The paper draws on ethnographic research among heroin user/sellers of Vietnamese ethnicity in a local Australian heroin marketplace. RESULTS: Temazepam was used in combination with heroin to enhance the experience of intoxication. Intense intoxication was desired for the pleasurable bodily sensations and emotional feelings it produced. The transgressive and dangerous nature of the practice added to its pleasure. Injection of temazepam capsules was also one of the practices constituting as well as expressing central social and cultural processes of heroin use in this particular social field. CONCLUSION: Despite embodied awareness of the harms associated with temazepam injection, these people were prepared to sacrifice 'health' for the pleasures they perceived to be afforded by injecting the gel capsules. My ethnographic analysis suggests that if harm reduction is to respond to high-risk practices such as these, then attention needs to be paid to the pleasures people derive from their practices, and to the social and cultural values these constitute and express.