The worldwide interest in cultivating quinoa (Chenopodium quinoa, Willd.) is mainly due to the plant's hardiness and its strong nutritional potential. It is one of the main foods of the Andean people before the Incas. The expansion of the crop that was until now considered relatively minor because it was geographically limited to a few Andean countries has raised several issues. The effort to promote the crop is part of a broader FAO (FAO: Food and Agriculture Organization of the United Nations) (UN) strategy to promote traditional or forgotten crops as a means to combat hunger and promote healthy eating. With experiments and field trials being conducted on every continent, it is well on its way of becoming a major crop for world agriculture and food. In February 2013, FAO Director-General José Graziano da Silva said, during the official launch of the International Year of Quinoa at New York UN Headquarters, that this can play an important role in eradicating hunger, malnutrition, and poverty. Many countries not only in South America are increasing production. This chapter addresses the key question of how it serves for increasing access to nutritious food. The issue is not only because of its nutritional value but also because smallholder farmers always currently produce the most part of quinoa internationally consumed. As the world faces the challenge of increasing the production of quality food to feed a growing population under climate changes, it offers a valuable alternative food source if we preserve practices that shape its characteristics. Thinking globally about the sustainable use, biodiversity could facilitate a paradigm shift in agricultural models, taking more account of nutrition as an approach to a broad agricultural development. Linking food nutrition and security to the use of water and energy in agriculture, to aspects of health for farmers and consumers, and to the protection of biodiversity in agroecosystems for adapting farming systems to climate change, that is probably the key for tomorrow's agriculture where quinoa appears as a model crop.