Nanotechnology possesses a wide array of materials in the form of nano-tubes, fibres, plates, chips, particles, sensors, and so on; the application of which has dramatically increased over the last few years due to their unique physicochemical characteristics (i.e., catalytic activity as well as optical, electronic, antibacterial, and magnetic properties). However, the exposure to nanoparticles, and consequent threat to human health and the environment are valid concerns because of the magnitude of nanotechnology-based applications, mainly in the pharmaceutical industries during drug designing, targeted drug delivery and disease diagnostics, and manufacturing of commercial products. For this purpose, the majority of nanomaterials are synthesized either from carbon (organic) and/or heavy metals, metal oxides (inorganic). Accordingly, lead, zinc, copper, chromium, iron, cadmium, and their oxides are important inorganic nanomaterials that are discussed in the chapter.