**1. Introduction**

*Opuntia ficus-indica* L. Mill, usually known as prickly pear, cactus pear or nopal, is a tropical or subtropical plant that belongs to the Cactaceae family, originally from arid and semiarid regions of America. This plant can grow in arid and semiarid climates, being the Cactaceae plant with the greatest economic relevance in the world [1]. It produces an edible and highly flavored fruit, known as "cactus pear," which is a berry with numerous seeds and thick peel, enclosing a delicately flavored pulp [2]. Their cladodes are also consumed, mainly in Mexico, which is the country with the largest area under cultivation and the largest producer [3, 4] but it is also cultivated in the United States, Spain, Italy, South Africa and Argentina, among other countries [5, 6]. Prickly pear fruit is commonly consumed in fresh, but it can also be consumed as juices, jam, syrups and other processed products. They are widely employed in Latin America. The current demand of prickly pear in Spain is increasing [4, 6].

There are ample evidences of the health benefits of consumption of prickly pear due to its source of nutrients and vitamins [4, 7, 8] and antioxidant properties due to its content of bioactive compounds [2, 9, 10]. Additionally, prickly pear presents medicinal uses: it is used in treatment of hyperglycemia and high levels of cholesterol [7, 11, 12] and its consumption is linked with lower incidence of coronary diseases and some types of cancer [8, 13], among others.

This chapter is focused on the nutritional composition, bioactive compounds and economic aspects of prickly pear fruits through a compilation and synthesis of the available studies. With this, the authors intend to contribute to the knowledge of *O. ficus-indica* and also to promote new scientific research and industrial use of this crop.
