Nanoparticles have revolutionized biomedicine, especially in the field of drug delivery due to their intriguing properties such as systemic stability, level of solubility, and target site specificity. It can, however, be both beneficial and damaging depending on the properties in different environments, thus highlighting the importance of nanotoxicology studies before use in humans. Green nanotechnology has drawn major attention because of its ecofriendly and economical biosynthetic protocols. Synthesis of metallic nanoparticles (NPs) using plant secondary metabolites is considered as a safer and cheaper option. Metallic nanoparticles (NPs) have a great role in many scientific fields such as medicine, physics, mechanics, pharmaceutics, and other. Plants contain phytochemicals that has been used traditionally for the treatment of various diseases, and proved to be nontoxic to healthy tissues. These phytochemicals play an important role in bio-reduction processes as reducing and stabilizing agents and renders NPs selective toxicity towards diseased tissues. This review focuses on the synthesis of certain metal and metal oxide nanoparticles (M/MO NPs) using an extract of Moringa oleifera plant. Moringa oleifera is an example of a tree with significant nutritional and therapeutic benefits. It is abundant in macronutrients, micronutrients, and other bioactive components that are essential for optimal bodily function and disease prevention. These components produce smaller particles and give a compelling impact on the activities of M/MO nanoparticles. This review paper is an attempt to compile up various research as well as reports related to nanoparticles such as FeO, CuO, ZnO, NiO, MgO, Ag, and Au.