Background: Nanoparticles can act as a carrier platform to ferry drugs to their target site of action to improve their activity and reduce the toxicity of some compounds, such as selenium, which acts as a cofactor for a variety of enzymes involved in oxido-reductive activities. Objective: This study suggested the implementation of Eruca sativa as a reducing agent to formulate selenium nanoparticles (SeNPs). Method: First, a 1% Eruca sativa extract solution will be dropped on 10 mM sodium selenite to produce a nanoselenium solution and characterize its physicochemical properties. Results: The prepared nano-selenium is monodispersed with a small particle size (39.4 nm), as confirmed by different characterization techniques. Conclusion: A 1% Eruca sativa extract solution has a powerful reducing effect that can be used in nanoselenium creation.