Nanotechnology is involved in the diagnosis and treatment of infectious and inflammatory diseases. It has shown a good role in regenerating, restoring and repairing damaged body parts, such as the heart, lungs and blood vessels. Nanoparticles (NPs) are helpful in osteoblasts formation and also used in the treatment of bone inflammation, skin infections, tuberculosis (TB), human immunodeficiency virus (HIV), Parkinson’s disease, atherosclerosis, cardiovascular and pulmonary diseases. They also assist the anti-inflammatory drugs in penetrating the skin. Platinum nanoparticles (NP) are used in bone allograft and dentistry while silver NPs possess an excellent potential against viruses, fungi and bacteria. For diagnostic purposes, nanoparticles are mostly used in the form of nanorobots, microchips and biosensors. Quantum dots give information about the tumor; the gold nano-particles are ideal to detect the antibodies of hepatitis and also for RNA and DNA delivery. Nanomaterials play an important role in the management of plant diseases and the activation of their defense mechanisms. The NPs of copper and silver are directly toxic to microorganisms while those of zinc, silicon, manganese, copper and boron have a function in host defense as a fertilizer and alter the nutritional status of the crop. Enzyme-based biosensors coated with Ti, Cu, Ag or Au-NPs greatly enhance the sensitivity of diagnostic probes for the detection of plant infections. The nano-Zn products have been effectively used to control viral, fungal, phytoplasma or bacterial diseases in crop plants. Nanoparticles are also used in packing edible food films.