Background <p>While rare, radiological and nuclear (RN) emergencies pose complex challenges that require tailored preparedness strategies. A key aspect is the strategic stockpiling of medical countermeasures (MCMs), yet existing literature offers limited and fragmented recommendations regarding their appropriate composition.</p> Methods <p>This systematic review, conducted following PRISMA guidelines, aims to consolidate and critically appraise available evidence on stockpiling for RN emergencies. Seven databases and selected grey literature sources were screened from 2011 onward. Studies were included if they provided direct or indirect recommendations on stockpiling items. Data extraction was conducted in two steps by independent pairs of reviewers, and identified items were categorized as therapeutics, medical devices, personal protective equipment (PPE), or RN-specific equipment. Items were further analyzed for regulatory status, administration route, shelf-life, and storage requirements.</p> Results <p>Thirty-two articles met the inclusion criteria. Therapeutics dominated the findings, with 50 distinct agents identified, most frequently potassium iodide, Prussian Blue, Ca-/Zn-DTPA, and hematopoietic growth factors such as filgrastim. In contrast, medical devices were not supported by a sufficient level of stockpiling recommendation, while PPE (6 of 32 articles) and RN equipment (14 of 32 articles) were cited less often. Pediatric considerations were rarely addressed, with 2 studies explicitly focused on this population. Gaps in operational guidance, regulatory harmonization, and standardized planning emerged across the literature.</p> Conclusions <p>This review highlights that stockpiling recommendations for RN emergencies remain limited, with greater guidance concentrated on a few therapeutics and little direction for other items. The findings provide an informative evidence base to support more consistent policy and preparedness planning.</p>