Health policies and programs are increasingly being driven by people from the community to more effectively address their needs. While a large body of evidence supports peer engagement in the context of policy and program development for various populations, little is known about this form of engagement among people who use drugs (PWUD). Therefore, a narrative literature review was undertaken to provide an overview of this topic. Searches of PubMed and Academic Search Premier databases covering 1995–2010 were conducted to identify articles assessing peer engagement in policy and program development. In total, 19 articles were included for review. Our findings indicate that PWUD face many challenges that restrict their ability to engage with public health professionals and policy makers, including the high levels of stigma and discrimination that persist among this population. Although the literature shows that many international organizations are recommending the involvement of PWUD in policy and program development, our findings revealed a lack of published data on the implementation of these efforts. Gaps in the current evidence highlight the need for additional research to explore and document the engagement of PWUD in the areas of policy and program development. Further, efforts to minimize stigmatizing barriers associated with illicit drug use are urgently needed to improve the engagement of PWUD in decision making processes.