Introduction Many predatory journals fail to follow best publication practices. Studies assessing the impact of predatory journals have focused on how these articles are cited in reputable academic journals. However, it is possible that research from predatory journals is cited beyond the academic literature in policy documents and guidelines. Given that research used to inform public policy or government guidelines has the potential for widespread impact, we will examine whether predatory journals have penetrated public policy.Methods and analysis This is a descriptive study with no hypothesis testing. Policy documents that cite work from the known predatory publisher OMICS will be downloaded from the Overton database. Overton collects policy documents from over 1200 sources worldwide. Policy documents will be evaluated to determine how the predatory journal article is used. We will also extract epidemiological details of the policy documents, including: who funded their development, the discipline the work is relevant to and the name of the organisations producing the policy. The record of scholarly citations of the identified predatory articles will also be examined. Findings will be reported with descriptive statistics using counts and percentages.Ethics and dissemination No ethical approval was required for this study since it does not involve human or animal research. Study findings will be discussed at workshops on journalology and predatory publishing and will be disseminated through preprint, peer-reviewed literature and conference presentations.