Australian young male prisoners with histories of injecting drug use are more likely to report injecting in prison, to do so more frequently, and to be involved in more un-safe injecting-related practices than their older counterparts. Despite international evidence that prison needle and syringe programs are both feasible and effective in reducing the harms associated with injecting drug use in prison, these young men do not have access to such equipment.We critically analyse the interview transcripts of 28 young men with histories of injecting drug use who were recently released from adult prisons in Victoria, Australia, and prison drug policy text. We use Bacchi's 'What's the problem represented to be?' approach to examine how the 'problem' of injecting drug use in prison is represented in prison drug policy, including the assumptions that underpin these problematisations, and the subjectification and lived effects that are produced for the young men in our study.Our analysis reveals how prison drug policy enables the creation and re-use of homemade injecting equipment crafted from unsterile items found in prison, and that in doing so the policy produces a range of stigmatising subjectification effects and other harmful material effects (such as hepatitis C virus transmission and injecting related injury and harms). Findings highlight, how injecting drug use is represented in policy silences other ways of understanding the 'problem' that may have less harmful effects for incarcerated young men who inject drugs.We argue that somewhat paradoxically, the approach of prohibiting access to sterile injecting equipment in prison-which is constituted as a solution for addressing such harms-in fact helps to produce them.