In general, metallic substrates react with their environment and progressively degenerate into a stable state such as oxide or hydroxide. Nanocrystalline metallic coatings are extensively used to protect metallic substrates against corrosion in a variety of industrial and household applications. When compared to conventional polycrystalline metallic coatings, nanocrystalline metallic coatings can significantly improve the metallic substrate's corrosion resistance, surface hardness, wear, and scratch resistance. This review has elucidated the influence of corrosion, nanocoating materials, different nanocoating techniques, and challenges associated with nanocoating. The goal is to include existing research on the beneficial impacts of nanocoating material structure, grain size, coating technique, additive concentration, and pH value on corrosive behaviour.