Tree nuts such as almonds, walnuts and pistachio have long been grown for consumption and as a food ingredient. It is estimated that 4 million metric tons of tree nuts are produced each year in over 40 countries. Demand is rising, in part because of research on the nutraceutical benefits of tree nuts. At the same time, these crops face particular challenges such as safety in the face of allergens and mycotoxin contamination. There is a need to increase production but in a more sustainable way in the face of climate change. This collection reviews the wealth of research addressing these challenges. Part 1 discusses the growing number of studies on the health benefits of tree nuts. Part 2 addresses safety issues. The remaining two parts assess advances in genetics and breeding of tree nuts, as well as advances in cultivation and the management of pests and diseases of tree nuts.