One of the more significant challenges for the planet is to secure sufficient food security and nutrition on a worldwide scale. A better and sustainable use of biodiversity is of critical importance and characterization of underused but highly nutritional fruit, and vegetable is a priority. This chapter discusses the functional research of eight Amazonian fruits. Four fruits are from trees, Spondias mombin, Myrciaria dubia, Genipa americana and the well-known Brazilian nut (Bertholletia excelsa). Four fruits from palm trees are described, Astrocaryum vulgare, Mauritia flexuosa, Bactris gasipaes and the well-known acai (Euterpe oleracea). Amazon fruits and nuts are the most abundant sources of bioactive compounds with antioxidant action, such as phenolic compounds, carotenoids, tocopherols, vitamin C, unsaturated fatty acids (UFA), terpenoids and steroids. Characteristic compounds, present in a higher amount, are a highlight for some fruits, such as vitamin C in camu-camu fruit, carotenoids in the peach palm and tucuma fruits, iridoids in genipap, and selenium and UFA in Brazil nut. The synergistic effect of all these compounds shows clear evidence of the health benefits of the consumption of these fruits associated with their high antioxidant capacity.