One of the most important basic foods in the world from a nutrition point of view is cereals. Nevertheless, the cereal processing industry generally produces large volumes of by-products, mainly formed by brans, germs, and husk. These by-products are produced in different stages of processing chains. In many cases, the by-products generated are considered as waste but in its composition it is possible to find equal or even more bioactive compounds that in the final product does. This chapter will examine current literature on both the recovery and use of valuable compounds obtained from the cereal waste and by-products, with a particular focus given to main cereals consumed by humans around the world, such as rice, wheat, and corn.