INTRODUCTION AND AIMS: In Australia, people who inject drugs (PWID) commonly report the use of benzodiazepines (BZDs). This paper explores the emerging use of alprazolam among PWID in Melbourne, Australia. DESIGN AND METHODS: This study reports on 3 years of data collected through the Victorian Illicit Drug Reporting System (2008-2010). Structured interviews were conducted with 451 PWID and analysed using odds ratios and χ(2)-tests for trends over time. RESULTS: While the proportion of PWID reporting recent BZD use remained stable over time, the proportion reporting alprazolam to be their most commonly used BZD fluctuated, peaking in 2009. Alprazolam users were significantly more likely to report using illicit BZDs and to report recent BZD injection compared with users of other BZDs. Alprazolam use was associated with the sale of drugs for cash, but not with other criminal activities. DISCUSSION AND CONCLUSION: The fluctuations in alprazolam use over time may be reflective of medical practitioners ceasing to prescribe alprazolam in response to reports of associated harms; however, this may in turn be driving the illicit alprazolam market. While the data do not indicate a clear association between alprazolam use and harms, considering the potential severity of associated harms and the association between alprazolam use and anterograde amnesia, patterns of alprazolam use among PWID should be closely monitored. Potential changes to prescribing practice should consider unintended consequences, such as replacement with other BZD types, or illicitly obtained BZDs.