Nutritional problems in the world are increasing, either because of a lack of food, or because food is not of sufficient quality, i.e., it does not provide the essential elements for the human diet and does not have the appropriate content of bioactive compounds. In either case, it is necessary to develop strategies to improve the quality of food for human consumption. In agriculture, nanotechnology can be an effective tool for solving food quality problems. Through the application of nanomaterials, it is possible to increase the content of essential elements in the consumption organs of plants, which are conventionally difficult to handle. But also, it is possible to increase the content of macromolecules and bioactive compounds, improving the quality of food, and therefore with beneficial effects for human health. It is for this reason that more knowledge of nanotechnology applied to agriculture is required in order to improve the nutritional quality of food. In this sense, the subject of this chapter is addressed, with emphasis on the biofortification of agricultural crops with the application of nanomaterials, and their impact on the content of essential elements and bioactive compounds.