Issues. Prescription drug monitoring programs are a harm minimisation intervention and clinical decision support tool that address the public health concern surrounding prescription drug misuse. Given the large number of studies published to date and the ongoing implementation of these programs, it is important to map the literature and identify areas for further research to improve practice. Approach. A scoping review was undertaken to identify the research on prescription drug monitoring programs published between January 2015 and April 2021. Key Findings. A total of 153 citations were included in this scoping review. The majority of the studies originated from the USA and were quantitative. Results on program effectiveness are mixed and mainly examine their association with opioid-related outcomes. Unintended consequences are revealed in the literature and this review also highlights barriers to program use. Implications. Overall, findings are mixed despite the large number of studies published to date. Mapping the literature identifies priority areas for further research that can advise policymakers and clinicians on practice improvement. Conclusion. Results on prescription drug monitoring program effectiveness are mixed and mainly examine their association with opioid-related outcomes. This review highlights barriers to prescription drug monitoring program effectiveness related to program use and system integration. Further research is needed in these areas to improve prescription drug monitoring program use and patient outcomes.