The harms associated with non-medical use of pharmaceutical opioid analgesics are well established; however, less is known about the characteristics and drug-use patterns of the growing and hidden populations of people using pharmaceutical opioids illicitly, including the frequency of pharmaceutical opioid injection. This paper aimed to undertake a detailed examination of jurisdictional differences in patterns of opioid use among a cohort of people who regularly tamper with pharmaceutical opioids in Australia. Data were drawn from the National Opioid Medications Abuse Deterrence study. The cohort was recruited from New South Wales (NSW; n = 303), South Australia (SA; n = 150) and Tasmania (TAS; n = 153) to participate in face-to-face structured interviews collecting data on use of pharmaceutical opioids, benzodiazepines, other sedative drugs and illicit substances, as well as the harms associated with substance use. TAS participants reported greater use and injection of certain pharmaceutical opioids (particularly morphine and methadone tablets), and limited heroin use, with lower rates of engagement in opioid substitution treatment, compared with NSW participants. NSW participants were more socially disadvantaged and more likely to report risky injecting behaviours and injecting-related injuries and diseases compared with SA and TAS participants. SA participants reported greater rates of pain conditions, greater use of pain-based services, as well as broader use of pharmaceutical opioids in regards to forms and route of administration, compared with NSW participants. Distinct jurisdictional profiles were evident for people who tamper with pharmaceutical opioids, potentially reflecting jurisdictional differences in prescribing regulatory mechanisms and addiction treatment models.