Maize is the third important cereal crop after wheat and rice. It is mainly utilized as feed, food, and fuel, or for other industrial purposes. It is consumed as a staple food in Africa, South America, and some parts of Asia. Nutritionally, maize contains ~70% starch, ~10% protein, ~2–5% oil, and a minor amount of flavanols, vitamins, and minerals. Starch is a major nutritional component of maize, and depending upon digestibility, is classified into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS). Its composition is genetically controlled and significant variation has been observed in the amylose to amylopectin ratio which affects the digestibility and makes it suitable for different industrial applications. Maize endosperm is a major source of protein for maize-consuming population, although the nutritional quality of maize protein is poor as it lacks essential amino acids viz., lysine and tryptophan. However, breeding efforts toward quality improvement have opened new ways for the development of high-quality protein maize. Maize is also a good source of oil, which is highly beneficial for human health as it reduces the cholesterol concentration in blood and used in cosmetic products and as surfactants. Naturally, maize is a rich source of carotenoids such as beta-carotene, zeaxanthin, lutein, and cryptoxanthin which serve as antioxidants in addition to other significant roles and health benefits. Maize is also a good source of micronutrients, including minerals such as iron, manganese, zinc, copper, and phosphorus. Many value-added products as well as fermented foods have been produced from maize which is consumed in different forms worldwide. A number of studies have been done toward developing the biofortified maize, and the present chapter focuses on all biochemical aspects of high-quality maize.