Nanotechnology is one of the fastest-growing and most promising modern technologies. It deals with the manufacturing and use of nanoparticles. Nanoparticles are generally known as small-sized particles possessing a size range of 1 to 100 nm. Due to their distinctive physicochemical and mechanical characteristics, they are utilized in various fields like agriculture, material science, food industry, medical, diagnostic, and cosmetic applications. One of the nanoparticles that is most frequently used nowadays is Zinc oxide nanoparticles. They have been explored for numerous biomedical applications, such as drug delivery, anticancer, antibacterial, antidiabetic, and bioimaging. Researchers expect that usage of Zinc oxide nanoparticles will expand so; the human body's exposure to them will increase. Zinc oxide .nanoparticles released into the environment could lead to adverse human and animal health effects. Recent studies concluded that Zinc oxide nanoparticles could cross some blood vital organs barriers and cell membranes, generate free radicals, and exhibit oxidative stress, cytotoxicity, and genotoxicity. Therefore, great attention must be taken to assess the toxicological aspects of nanoparticles.